Chimeric receptors comprising janus kinase for regulating cellular pro liferation

ABSTRACT

The present invention is directed to novel chimeric proliferation receptor proteins and DNA sequences encoding these proteins where the chimeric proteins are characterized in three general categories. In one category, the novel chimeric proteins comprise at least three domains, namely, an extracellular inducer-responsive clustering domain capable of binding an extracellular inducer that transmits a signal to a proliferation signaling domain, a transmembrane domain and a proliferation signaling domain that signals a host cell to divide. In the second category, the novel chimeric proteins comprise at least two domains, namely, an intracellular inducer-responsive clustering domain capable of binding an intracellular inducer and a proliferation signaling domain that signals the cell to divide. In yet a third category, a novel hybrid chimeric protein receptor is contemplated that contains an intracellular or extracellular inducer domain, a transmembrane domain, a proliferation signaling domain and an effector signaling domain in a single chain molecule. Whether the binding domain is intracellular or extracellular, the binding of inducer to these novel chimeric receptor proteins induces the clustering of the binding domains to each other and further signals the cell to proliferate, and optionally, signal an effector function. The present invention further relates to expression vectors containing the nucleic acids encoding the novel chimeric receptors, cells expressing the novel chimeric receptors and therapeutic methods of using cells expressing these novel receptors for the treatment of cancer, infectious disease and autoimmune diseases, for example.

This application is a continuation of application Ser. No. 08/382,846,filed Feb. 2, 1995, which is pending.

INTRODUCTION

1. Technical Field

The field of this invention relates to the construction and use of novelchimeric receptor proteins for signaling cellular proliferation andoptionally, for signaling cellular effector function.

2. Background

The production of novel chimeric receptor proteins which initiatesignaling in a cell that results in activating a second messengerpathway in response to an inducer binding to the extracellular portionof these receptors is the subject of U.S. Pat. No. 5,359,046, theentirety of which is incorporated herein by reference. These chimericreceptor molecules comprise three domains in a single protein moiety,namely, a cytoplasmic effector function signaling domain, atransmembrane domain and an extracellular inducer binding domain. Thecytoplasmic domain and extracellular domain are not naturally associatedtogether. By mixing and matching extracellular domains with a particulartype of cytoplasmic domain, one may transduce a particular signal byemploying different inducers that bind to different extracellularbinding domain receptors. Additionally, these single molecule receptorshave the desired characteristics of binding inducer and transducing asignal without requiring the major histocompatibility complex (MHC)involvement or antigen presentation. Such characteristics make thesechimeric receptors ideal in the development of cellular therapies bypermitting the directed activity of cells selected for a particulareffector function.

To enhance the above technology, it would be desirable to insure thatcells expressing these chimeric receptors with effector function arepresent in the body in sufficient quantity for effective cellulartherapy or treatment. This requirement may be met by the proliferationof the cells expressing the chimeric effector function receptor at thesite where they would be most advantageous.

The present invention provides a strategy that consists of furtherengineering cells, including those expressing chimeric effector functionreceptors such that they are capable of proliferating in the body in aninducer molecule driven fashion and, in addition, may be growth factorindependent.

There is also a general need in the field for a variety of therapeuticcells to proliferate in vivo either when they have homed to or aretransplanted to the proper site or in response to an administeredinducer molecule. The present invention provides a method to direct cellproliferation in this manner.

SUMMARY OF THE INVENTION

Methods involving recombinant DNA technology and recombinant proteinexpression are provided for the production and expression of novelchimeric receptors for regulating cellular proliferation and optionally,for signaling effector function. In one general embodiment, the novelchimeric proliferation receptor proteins comprise at least anextracellular inducer-responsive clustering domain that binds to anextracellular inducer, a transmembrane domain that crosses the cellmembrane, and a cytoplasmic proliferation signaling domain that signalsthe cell to divide upon the clustering of the extracellular domains.This novel chimeric proliferation receptor may optionally have aneffector function signaling domain between the transmembrane domain andthe proliferation signaling domain or it may be attached to theC-terminus of the proliferation signaling domain. In another generalembodiment, the novel chimeric proliferation receptor proteins compriseat least an intracellular inducer-responsive clustering domain thatbinds to an intracellular inducer, and a cytoplasmic proliferationsignaling domain that signals the cell to divide upon the clustering ofthe intracellular domains. This novel chimeric proliferation receptormay optionally have an effector function signaling domain attached viaits N-terminus to the proliferation signaling domain or to theintracellular inducer-responsive clustering domain. Modifications ofthese receptors include amino acid substitutions or deletions of thedomains, or the additions of one or more linker regions between variousdomains of these novel chimeric proliferation receptors.

The present invention also includes the preparation and expression ofnovel chimeric proliferation receptor proteins or modifications thereofby transducing into a host cell a DNA construct comprising a DNAfragment or variant thereof encoding the above novel chimericproliferation receptor(s) functionally attached to regulatory sequencesthat permit the transcription and translation of the structural gene andexpression in the host cell containing the DNA construct of interest.

The present invention further includes DNA fragments and variantsthereof encoding the novel chimeric proliferation receptors includingthe expression vectors comprising the above DNA fragments or variantsthereof, host cells transduced with the above expression vectors andmethods of using the novel chimeric proliferation receptors to regulatecell growth or as therapeutics for treating cancer and infectiousdiseases.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the structures of the chimeric proliferationreceptors discussed in the detailed description.

FIG. 2 is a listing of oligonucleotides (SEQ ID NOS:1-30) as describedin the Examples, infra.

FIGS. 3 (A)-(L) are graphs of FACS analysis of CD4-Janus kinase chimericproliferation receptor expression in 293 cells, as described in Example10(B), infra. The dotted lines are cells stained with FITC-IgG; thesolid lines are cells stained with FITC-anti-CD4. (FIG. 3(A):Mock-transfected; FIG. 3(B) CD4-ζ; FIG. 3(C) CD4-mJAK1; FIG. 3(D)CD4-ζ-mJAK1; FIG. 3(E) CD4-mJAK2; FIG. 3(F) CD4-ζ-mJAK2; FIG. 3(G)CD4-mJAK3; FIG. 3(H) CD4-ζ-mJAK3; FIG. 3(I): CD4-hJAK3; FIG. 3(J)CD4-ζ-hJAK3; FIG. 3(K): CD4-hTyk2; FIG. 3(L): CD4-ζ-hTyk2.)

FIG. 4 is an autoradiogram of immunoprecipitations of lysates from 293cells transfected with CD4-Janus kinase constructs as described inExample 10(C). (Lanes 1 & 4: Mock-transfected; Lanes 2 & 5: CD4-mJAK1;Lanes 3 & 6: CD4-mJAK3; Lanes 1-3: no antibody and Lanes 4-6: OKT4Aantibody.)

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As noted above, the present invention generally relates to novelchimeric proliferation receptor proteins and DNA sequences encodingthese novel chimeric receptor proteins which may or may not additionallycontain an effector function signaling domain. The novel chimericproliferation receptors (CPRs) provided herein may be furthercharacterized in that the inducer binding domain of the CPR is expressedextracellularly or intracellularly. CPRs may be introduced into cellsalready expressing a chimeric effector function receptor previously asdescribed in U.S. Pat. No. 5,359,046 or the two receptors may beintroduced together and co-expressed in the same cell. In this aspect,the CPR containing cells of the present invention have the distinctadvantage of specific expansion in response to a specific inducermolecule that may simultaneously stimulate effector function in the sameexpanded cell population. Alternatively, CPRs of the present inventionmay be introduced into cells without a chimeric effector functionreceptor, to allow them to proliferate in vivo. Further aspects of thepresent invention will be discussed in detail below following adefinition of terms employed herein.

Definitions

The term "extracellular inducer-responsive clustering domain" or "ECD"refers to the portion of a protein of the present invention which isoutside of the plasma membrane of a cell and binds to at least oneextracellular inducer molecule as defined below. The ECD may include theentire extracytoplasmic portion of a transmembrane protein, a cellsurface or membrane associated protein, a secreted protein, a cellsurface targeting protein, a cell adhesion molecule, or a normallyintracytoplasmic ligand-binding domain, and truncated or modifiedportions thereof. In addition, after binding one or more inducermolecule(s), the ECDs will become associated with each other bydimerization or oligomerization, i.e., "cluster".

The term "intracellular inducer-responsive clustering domain" or "ICD"refers to the portion of a protein which is inside of the plasmamembrane of a cell, that binds to at least one intracellular inducermolecule as defined below. After binding one or more inducermolecule(s), the ICDs will become associated with each other bydimerization or oligomerization, i.e., "cluster".

The term "proliferation signaling domain" or "PSD" refers to a proteindomain which signals the cell to enter mitosis and begin cell growth.Examples include the human or mouse Janus kinases, including but notlimited to, JAK1, JAK2, JAK3, Tyk2, Ptk-2, homologous members of theJanus kinase family from other mammalian or eukaryotic species, the IL-2receptor β and/or γ chains and other subunits from the cytokine receptorsuperfamily of proteins that may interact with the Janus kinase familyof proteins to transduce a signal, or portions, modifications orcombinations thereof.

The term "transmembrane domain" or "TM" refers to the domain of theprotein which crosses the plasma membrane and is derived from theinducer-binding ECD domain, the effector function signaling domain, theproliferation signaling domain or a domain associated with a totallydifferent protein. Alternatively, the transmembrane domain may be anartificial hydrophobic amino acid sequence which spans the plasmamembrane.

The term "extracellular inducer molecule" refers to a ligand or antigenwhich binds to and induces the clustering of an ECD as described aboveor portions or modifications of the extracellular inducer molecule thatare still capable of binding to and inducing the clustering of an ECD.To facilitate clustering, the inducer molecule may be intrinsicallybivalent or multivalent; or it may be presented to the ECD in a bivalentor multivalent form, eg., on the surface of a cell or a virus.

The term "intracellular inducer molecule" refers to a natural orsynthetic ligand that can be delivered to the cytoplasm of a cell, andbinds to and induces the clustering of an intracellular inducerresponsive domain. To facilitate clustering, the intracellular inducermolecule may be intrinsically bivalent or multivalent.

The term "chimeric extracellular inducer-responsive proliferationreceptor" or "CEPR" refers to a chimeric receptor that comprises anextracellular inducer responsive clustering domain (ECD), atransmembrane domain and a proliferation signaling domain (PSD). The ECDand PSD are not naturally found together on a single receptor proteinOptionally, this chimeric receptor may also contain an effector functionsignaling domain as defined below.

The term "chimeric intracellular inducer-responsive proliferationreceptor" or "CIPR" refers to a chimeric receptor that comprises anintracellular inducer-responsive clustering domain (ICD) and aproliferation signaling domain (PSD). The ICD and PSD are not naturallyfound together on a single receptor protein. Optionally, this chimericreceptor may also contain an effector function signaling domain asdefined below.

The term "effector function" refers to the specialized function of adifferentiated cell. Effector function of a T cell, for example, may becytolytic activity or helper activity including the secretion ofcytokines.

The term "effector function signaling domain" or "EFSD" refers to theportion of a protein which transduces the effector function signal anddirects the cell to perform its specialized function. While usually theentire EFSD will be employed, in many cases it will not be necessary touse the entire chain. To the extent that a truncated portion of the EFSDmay find use, such truncated portion may be used in place of the intactchain as long as it still transduces the effector function signal.Examples are the ζ chain of the T cell receptor or any of its homologs(e.g., η chain, FcεR1-γ and -β chains, MB1 chain, B29 chain, etc.), CD3polypeptides (γ, δ and ε), syk family tyrosine kinases (Syk, ZAP 70,etc.), the src family tyrosine kinases (Lck, Fyn, Lyn, etc.) and othermolecules involved in T cell signal transduction.

The term "chimeric effector function receptor" refers to a chimericreceptor that comprises an extracellular domain, transmembrane domainand cytoplasmic domain as described in U.S. Pat. No. 5,359,046 or theEFSD domain as described above. The extracellular domain serves to bindto an inducer and transmit a signal to the cytoplasmic domain whichtransduces an effector function signal to the cell.

The term "modifications" refers to an addition of one or more aminoacids to either or both of the C- and N-terminal ends of theintracellular and extracellular inducer molecules (in the case wherethese are proteins) or, the ECDs, ICDs, PSDs, EFSDs, or TMs, asubstitution of one or more amino acids at one or more sites throughoutthese proteins, a deletion of one or more amino acids within or ateither or both ends of these proteins, or an insertion of one or moreamino acids at one or more sites in these proteins such that the inducermolecule binding to the ICD or the ECD is retained or improved asmeasured by binding assays known in the art, for example, Scatchardplots, or such that the PSD, EFSD or TM domain activities are retainedor improved as measured by one or more of the proliferation assaysdescribed below. In addition, modifications can be made to theintracellular and extracellular inducer molecules and to thecorresponding ICDs and ECDs to create an improved receptor-ligandbinding pair.

The term "variant" refers to a DNA fragment encoding an intracellular orextracellular inducer molecule, or an ECD, ICD, PSD, EFSD or TM domainthat may further contain an addition of one or more nucleotidesinternally or at the 5' or 3' end of the DNA fragment, a deletion of oneor more nucleotides internally or at the 5' or 3' end of the DNAfragment or a substitution of one or more nucleotides internally or atthe 5' or 3' end of the DNA fragment such that the inducer moleculebinding to the ICD or the ECD is retained or improved as measured bybinding assays known in the art, for example, Scatchard plots, or suchthat the PSD, EFSD or TM domain activities are retained or improved asmeasured by one or more of the proliferation assays described below. Inaddition, modifications can be made to the intracellular andextracellular inducer molecules and to the corresponding ICDs and ECDsto create an improved receptor-ligand binding pair.

The term "linker" or "linker region" refers to an oligo or polypeptideregion of from about 1 to 30 amino acids that links together any of theabove described domains of the chimeric proliferation receptors definedabove. The amino acid sequence is not derived from the ICDs, ECDs,EFSDs, PSDs, or TM domains. Examples of linker regions are linker 212and linker 205 as referenced in Betzyk et al., J. Biol. Chem.,265:18615-18620 (1990) and Gruber et al., J. Immunol., 152:5368-5374(1994) respectively.

In its general embodiments, the present invention relates to novelchimeric proliferation receptors, nucleic acid sequences encoding thereceptors, the vectors containing the nucleic acid sequences encodingthe receptors, the host cells expressing the receptors, and methods ofusing of the receptors in regulating cell growth. In one aspect of thepresent invention, a novel chimeric proliferation receptor (CPR) proteinis provided containing an inducer-responsive binding domain and aproliferation signaling domain that do not naturally exist together as asingle receptor protein. One novel CPR identified herein as "chimericextracellular inducer responsive proliferation receptor" (abbreviatedCEPR) is designed to be expressed in cells, which then proliferate inresponse to the binding of a specific extracellular inducer molecule.The three domains that comprise CEPR are: (1) an extracellularinducer-responsive clustering domain (ECD) which serves to bind to aligand called an extracellular inducer molecule, (2) a transmembranedomain (TM), which crosses the plasma membrane and, (3) a proliferationsignaling domain (PSD) that signals the host cell to divide. Optionally,the CEPRs described above may comprise multiple PSDs attached to eachother (See FIG. 1(a)). Each inducer molecule or group of inducermolecules is presented multivalently (eg. more than one inducer moleculein close proximity to each other on a cell surface) to the CEPR. Theinducer molecules will thus bind more than one ECD, causing the ECDs todimerize or oligomerize (i.e. cluster together). This clusteringtransmits a signal through the transmembrane domain to the proliferationsignaling domains, which become activated.

The host cells bearing the chimeric proliferation receptors of thepresent invention will expand in number in response to the binding of aspecific extracellular inducer molecule, to the extracellularinducer-responsive clustering domain (ECD) of the CEPR. These ECDSinclude but are not limited to the following types of clusteringdomains: a cell surface or membrane associated molecule (eg, CD4, CD8,etc.), a secreted targeting molecule (eg., Interleukin-14 (IL-14),etc.), a cell surface/secreted targeting molecule (eg, antibody (Ab),single-chain antibody (SAb), antibody fragments, etc.), a cell adhesionmolecule (e.g., ICAM, LFA-1, etc.), or portions or modification thereof.In each instance, the extracellular inducer molecules bind to theextracellular domains of the CEPR which results in the dimerization oroligomerization of the extracellular inducer responsive domains andhence, the dimerization or oligomerization (i.e. "clustering") of theproliferation signaling domains results in the transduction of a signalfor cell growth.

If the chimeric extracellular inducer-responsive proliferation receptor(CEPR) of the present invention is expressed in host cells alreadyexpressing the chimeric effector function receptor of U.S. Pat. No.5,359,046 described hereinabove (for example, CD4/zeta chimericreceptor), and binds to the same inducer as the CEPR, eg. CD4, thenthese dual chimeric receptor expressing cells will proliferate uponaddition of the same inducer that drives effector function, eg.cytotoxicity. Alternatively, the inducer that binds to the extracellularbinding domain of the chimeric effector function receptor may differfrom the inducer molecule that binds to the ECD of the CEPR. In thiscase, one may separate cell growth (proliferation) from effectorfunction in the same cell by stimulating with different inducermolecules.

In another aspect of the present invention, a novel chimericproliferation receptor containing the proliferation signaling domain andeffector function signaling domain together in the same protein receptoris provided. In this embodiment, the chimeric receptor comprises thethree domains contained in the CEPR and additionally comprises aneffector function signaling domain. Thus, the extracellular inducerresponsive clustering domain (ECD) of the CEPR is linked via atransmembrane domain to two signal transducing domains. One signaltransducing domain mediates the effector function signal while the othersignal transducing domain mediates the proliferation signal, (forexample, CD4-ζ-JAK1). Either the proliferation signaling domain or theeffector function signaling domain may be linked to the transmembranedomain and is further linked on its 3' end to the second signalingdomain either directly or through a linker region. Optionally, more thanone PSD may be attached directly, or through a linker, to each other toform a CEPR with multiple PSDs (FIG. 1(b) and (c)). It is contemplatedthat the preparation of this novel chimeric proliferation/effectorfunction chimeric receptor will activate proliferation and effectorfunction simultaneously in a host cell upon the binding of extracellularinducer molecules to the ECD of the receptor.

In another embodiment, the present invention relates to a second generalcategory of chimeric proliferation receptors called "chimericintracellular inducer-responsive proliferation receptors" or "CIPRs"Cells constructed to express CIPRs proliferate in response to a specificligand, called an intracellular inducer molecule. This proliferationreceptor contains at least two domains: (1) an intracellularinducer-responsive clustering domain (ICD) which serves to bind to aligand called an intracellular inducer molecule, and (2) a proliferationsignaling domain (PSD) that signals the cell to divide (as an example,FKBP-JAK1). The two domains comprising a CIPR may be constructed suchthat either the ICD or the PSD is at the N-terminus of the CIPR. Alinker region such as linker 212 (Betzyk et al., J- Biol. Chem.265:18615-18620 (1990)) may also be inserted between the two domainsthat comprise CIPRs. Each inducer molecule binds two or more ICDs,causing them to dimerize or oligomerize (i.e. cluster together). Thisclustering of the ICDs causes the proliferation signaling domains tobecome activated. A transmembrane domain is not required but may be usedin the construction of these novel intracellular proliferationreceptors. Optionally, a myristylation-targeting domain may be linked tothe N-terminus of the ICD or the PSD to allow for membrane association(Cross et al., Mol. Cell. Biol., 4:1834-1842 (1984), Spencer et al,Science 262:1019-1024 (1993)). An additional option may be to constructa CIPR with more than one PSD attached directly, or through a linker, toeach other (FIG. 1(d) and (e). CIPRs may be used in any host cell typefor which there is a desire for regulated expansion of a therapeuticcell such as in transplantation therapy, as described infra.

The host cells bearing CIPRs of the present invention will expand innumber upon binding of an intracellular inducer molecule to theintracellular inducer-responsive clustering domain (ICD) of the CIPR.These inducer molecules include but are not limited to the followingligands: natural or synthetic ligands that bind to and induce theclustering of an intracellular inducer responsive domain such asimmunophilins (e.g., FKBP), cyclophilins, and steroid receptors.

The CIPRs of the present invention may also be expressed in host cellspreviously engineered with the chimeric effector function receptordescribed hereinabove. Upon addition of an extracellular inducermolecule and an intracellular inducer molecule, these cells willactivate the effector function (provided by signaling through thechimeric effector function receptor) and divide (provided by signalingthrough the CIPR). Alternatively, the inducer that binds to theextracellular binding domain of the chimeric effector function receptormay be the same inducer as the one that binds to the ICD of the CIPR ifthe inducer is a intracellular inducer molecule which can be deliveredto the cytoplasm of the host cell. In this situation, cell growth andeffector function would be activated simultaneously in the same cellupon presentation of the intracellular inducer molecule.

In another aspect of the present invention, a novel chimeric proteinreceptor containing a proliferation signaling domain and effectorsignaling domain is provided together in the same intracellularinducer-responsive receptor (FIG. 1(f) through (k)). In this embodiment,a hybrid receptor is constructed as one protein comprising the twodomains described in the CIPR of the present invention, and additionallycomprising an effector function signaling domain (EFSD). Thus, theintracellular inducer responsive clustering domain (ICD) is directlyconnected to the proliferation signaling domain (PSD) which in turn isdirectly attached to an effector function signaling domain (FIG. 1(f)).Alternatively, the ICD may be directly connected to an effector functionsignaling domain which in turn is directly connected to a proliferationsignaling domain (FIG. 1(g)). In yet another conformation of the presentembodiment, either the EFSD or the PSD may be associated with themembrane via a myristylation domain or a TM domain, for example. TheEFSD or the PSD is attached at its C terminus to a PSD or EFSD,respectively, which in turn is attached at its C terminus to one or moreICDs (FIG. 1(h) and (i)). In addition, CIPR proliferation/effectorfunction receptors may be constructed by linking together the followingdomains (N to C terminal): a membrane-associated PSD or EFSD, followedby one or more ICDs, followed by the EFSD or PSD domain, respectively,(FIG. 1(j) and (k)). It is also possible to separate one or more domainsfrom each other in the hybrid proliferation/effector receptors of thepresent embodiments with a linker region such as linker 205 (Gruber etal, J. Immunol., 152:5368-5374 (1994)). Upon introduction of these novelhybrid chimeric proliferation/effector function receptors into cells,one may modulate the signaling of a proliferative response and effectorfunctional response by the addition of one or more intracellular inducermolecules.

In yet another aspect of the present invention, a novel hybrid chimericproliferation receptor containing an extracellular inducer-responsiveclustering domain (ECD), an intracellular inducer-responsive clusteringdomain (ICD), and a proliferation signaling domain (PSD) is providedtogether in the same receptor protein. In this embodiment, a hybridinducer binding receptor is constructed as one protein comprising in theN-terminal to C-terminal direction an ECD, transmembrane domain, an ICDand a proliferation signaling domain (FIG. 1(1)). Alternatively, ahybrid inducer binding receptor is constructed as one protein comprisingin the N-terminal to C-terminal direction an ECD, transmembrane domain,PSD and an ICD (FIG. 1(m)). In preparing the hybrid inducer bindingreceptors of the present embodiment, one may separate one or moredomains of each receptor with a linker. Additionally, more than one ICDand PSD may be attached directly or via a linker to each other to formmultiple ICDs and PSDs. Upon introduction of these novel hybridinducer-binding chimeric proliferation receptors into a host cell, onemay modulate proliferation of the cell by either an extracellularinducer, an intracellular inducer or a combination of these twodifferent inducer molecules.

In still another embodiment, the present invention provides a chimericproliferation receptor described above containing an ECD, TM, ICD andPSD (N- to C-terminal) that additionally contains an effector functionsignaling domain (EFSD) attached at the N-terminal (FIG. 1(o)) orC-terminal (FIG. 1(n)) end of the PSD. Multiple ECDs, ICDs and/or PSDsmay be used in the construction of the above receptors. Additionalembodiments of hybrid CPRs containing one or more ICD(s) and ECD(s) andone or more PSD(s) and one EFSD are contemplated that comprise thefollowing four conformations (N- to C-terminus): ECD(s), TM, PSD(s),EFSD and ICD(s) (FIG. 1(p)); ECD, TM, EFSD, PSD and ICD (FIG. 1(q));ECD(s), TM, PSD(s), ICD(s) and EFSD (FIG. 1(r)); and ECD(s), TM, EFSD,ICD(s) and PSD(s) (FIG. 1(s)). Upon expression of these novelproliferation/effector receptors in a host cell, one may modulateproliferation and effector signaling by adding either an extracellularinducer, an intracellular inducer or a combination of these twodifferent inducer molecules.

The proliferation signaling domains (PSDs) that comprise the chimericproliferation receptors (CPRs) of the present invention (both CIPRs andCEPRs) may be obtained from the cytoplasmic signal-transducing domainsof the cytokine/hematopoietin receptor superfamily. The members of thismammalian receptor superfamily can transduce proliferative signals in awide variety of cell types. These receptors are structurally related toeach other. The cytoplasmic domains of the signal-transducing subunitsmay contain conserved motifs that are critical for transduction ofproliferative signals (Bazan, Current Biology, 3:603-606 (1993); Boulayand Paul, Current Biology, 3:573-581 (1993); Wells, Current Opinion inCell Biology, 6:163-173 (1994); Sato and Miyajima, Current Opinion inCell Biology, 6:174-179 (1994); Stahl and Yancopoulos, Cell, 74:587-590(1993), Minami et al., Ann. Rev. Immunol., 11:245-267 (1993); Kishimotoet al., Cell, 76:253-262 (1994)). In contrast to the growth factorreceptors previously described in chimeric receptors (Schlessinger andUllrich , Cell, 61:203-212 (1990), Ullrich and Schlessinger, Neuron,9:383-391 (1992)), the cytoplasmic portions of the cytokine receptorsuperfamily proteins that comprise the PSDs employed in the presentinvention do not contain any kinase domains or other sequences withrecognizable catalytic function. Further, although the growth factorreceptors described by Ullrich and the cytokine receptors employed inthe present invention both dimerize upon binding of inducer, thedimerized growth factor receptors activate their intrinsic receptorkinase activity, while the dimerized cytokine receptors employed in thepresent invention stimulate the activity of associated tyrosine kinases(Kishimoto et al., Cell, 76:253-262 (1994)). The signal-transducingcomponents of the cytokine receptors to be used in the PSDs of thepresent invention include, but are not limited to, Interleukin-2receptor β (IL-2Rβ), IL-2Rγ, IL-3Rβ, IL-4R, IL-5Rα, IL-5Rβ, IL-6R, IL-6Rgp130, IL-7R, IL-9R, IL-12R, IL-13R, IL-15R, EPO-R (erythropoietinreceptor), G-CSFR (granulocyte colony stimulating factor receptor),GM-CSFRα (granulocyte macrophage colony stimulating factor receptor α)GM-CSFRβ, LIFRα (leukemia inhibitory factor receptor α), GHR (growthhormone receptor), PRLR (prolactin receptor), CNTFR (ciliaryneurotrophic factor receptor), OSMR (oncostatin M receptor) IFNRα/β(interferon α/β receptor), IFNRγ, TFR (tissue factor receptor), and TPOR(thrombopoietin or mpl-ligand receptor)(Minami et al., J. Immunol.,152:5680-5690 (1994); Boulay and Paul Current Biology, 3:573-581 (1993);Wells, Current Opinion in Cell Biology, 6:163-173 (1994)).

The IL-2, IL-3 and IL-6 subfamilies of the above cytokine receptorsuperfamily, which are active in many different cell types, may supplythe PSDs of the CPRs of the present invention. The IL-2 receptorsubfamily includes, but is not to be limited to, the receptors for IL-2,IL-4, IL-7, IL-9, IL-13 and IL-15. IL-2R, IL-4R, IL-7R, IL-9R, IL-13Rand IL-15R share IL-2Rγ, one of the signal transducing components of theIL-2R (Noguchi et al., Science, 262:1877-1880 (1993); Russel et al.,Science, 262:1880-1884 (1993); Minami et al., J. Immunol., 152:5680-5690(1994)). IL-2R and IL-15R share a second transducing component, IL-2Rβ(Giri et al., EMBO J., 13:2822-2830 (1994)). These cytokines act on awide variety of cell types, for example, B cells, T cells including LAKcells and thymocytes, NK cells, and oligodendroglial cells (Kishimoto etal., Cell, 76:253-262 (1994)). In addition, high affinity receptors toIL-15 are found on myeloid cells, vascular endothelial cells, and onstromal cells types from bone marrow, fetal liver and thymic epithelium(Giri et al., EMBO J., 13:2822-2830 (1994)). The IL-3 receptor subfamilyincludes, but is not limited to, the receptors for IL-3, IL-5 and GM-CSF(Sato and Miyajima, Current Opinion in Cell Biology, 6:174-179 (1994)).These cytokine receptors contain a common signal-transducing, or β chainwhich has a large cytoplasmic domain whose membrane proximal region iscritical for c-myc induction and proliferative signaling activity(Quelle et al., Mol. Cell. Biol., 14:4335-4341 (1994)). This family ofcytokines act on overlapping cell types during hematopoiesis includingblast cells, granulocytes, macrophages, monocytes and eosinophils(Kishimoto et al., Cell, 76:253-262 (1994)). The IL-6 receptor subfamilyincludes, but is not limited to, the receptors for IL-6, CNTF, LIF, OSM,IL-11, G-CSFR and IL-12. IL-6R, CNTFR, LIFR and OSMR have a commonsignal -transducing chain (gp130) with a cytoplasmic domain whosemembrane proximal region is critical for signaling activity (Sato andMiyajima, Current Opinion in Cell Biology, 6:174-179 (1994), Narazaki etal., Proc. Natl. Acad. Sci., 91:2285-2289 (1994)). These cytokines acton a wide variety of cell types, including ciliary, sympathetic, sensoryand motor neurons, embryonic stem cells, control of the differentiationof B cells, plasmacytomas, megakaryocytes, myeloid cells, osteoclasts,and hepatocytes (Kishimoto et al., Cell, 76:253-262 (1994)). Othermembers of the cytokine receptor superfamily which may be a part of theabove subfamilies, or may be members of novel subfamilies include thereceptors for EPO, TPO, GH and PRL, which are also found on many celltypes (Wells, Current Opinion in Cell Biology, 6:163-173 (1994), Stahland Yancopoulos, Cell, 74:587-590 (1993)). The more distantly relatedIFNα/β and IFNγ receptors, found in most cell types also containcytoplasmic domains of related structure (Farrar and Schreiber, Annu.Rev. Immunol. 11:571-611 (1993), Taga and Kishimoto, FASEB J.,6:3387-3396 (1992)).

The proliferation signaling domains employed in constructing the CPRs ofthe present invention may also be obtained from any member of the Janusor JAK eukaryotic family of tyrosine kinases, including Tyk2, JAK1,JAK2, JAK3 and Ptk-2. Members of the Janus kinase family are found inall cell types. They associate with various signal transducingcomponents of the cytokine receptor superfamily discussed above andrespond to the binding of extracellular inducer by the phosphorylationof tyrosines on cytoplasmic substrates (Stahl and Yancopoulos, Cell,74:587-590 (1993)). They are thus an integral part of the control ofcell proliferation in many different kinds of cells. The members of thisfamily are marked by similar multidomain structures and a high degree ofsequence conservation. Unique among tyrosine kinases, the Janus kinasefamily may have two non-identical tandem kinase- like domains, only oneof which may have catalytic activity (Firmbach-Kraft et al., Oncogene,5:1329-1336 (1990); Wilks et al., Mol. Cell. Biol., 11:2057-2065 (1991);Harpur et al., Oncogene, 7:1347-1353 (1992)). The Janus kinases used inthe present invention, unlike the src kinases, do not have src homologysequences (SH2, SH3) or a consensus sequence for myristylation. Unlikethe receptor tyrosine kinases (RTK), the Janus kinases are not membraneproteins and do not contain transmembrane spanning domains (Ullrich andSchlessinger, Neuron, 9:383-391 (1992)). The kinase activity of theJanus kinases is usually activated after the binding of inducers totheir associated cytokine family receptors and the oligomerization ofthe receptors (Stahl and Yancopoulos, Cell, 74:587-590 (1993)). Thisactivation, in turn, triggers the initiation of intracellular signalingcascades.

JAK3 can be employed as a PSD in any of the CPRs of the presentinvention. Its activation by IL-2 parallels c-myc induction and theonset of DNA synthesis. JAK3 is involved with IL-2, IL-4 and IL-7induced stimulation of T, NK and myeloid cells (Witthuhn et al., Nature,370:153-157 (1994); Russell et al., Science, 366:1042-1044 (1994);Kawamura et al., Proc. Natl. Acad. Sci., 91:6374-6378 (1994); Miyazakiet al., Science, 266:1045-1047 (1994); Johnston et al., Nature,370:151-153 (1994); Asao et al., FEBS Letters, 351:201-206 (1994), Zenget al., FEBS Letters, 353:289-293 (1994)) JAK2, a component of growthfactor signaling in a wider variety of cells, can also be used in theCPRs of the present invention. It is activated by EPO, GH, prolactin,IL-3, GM-CSF, G-CSF, IFNγ, LIF, OSM, IL-12 and IL-6 (Watling et al.,Nature, 366:166-170 (1993); Witthuhn et al., Cell, 74:227-236 (1993);Argetsinger et al., Cell, 74:237-244 (1993); Stahl et al., Science,263:92-95 (1994); Narazaki et al., Proc. Natl. Acad. Sci.,91:2285-2289(1994); Quelle et al., Mol. Cell. Biol., 14:4335-4341(1994); Silvennoinen et al., Nature, 366:583-585 (1993); Darnell et al.,Science, 264:1415-1421 (1994)Campbell et al, Proc. Natl. Acad. Sci.,91:5232-5236 (1994), Bacon et al., J. Exp. Med., 181:399-404 (1995);(Harpur Oncogene 7: 1347-1353, 1992)). The present invention alsocontemplates the use of JAK1 as a PSD in the present invention. Itsactivity is also promiscuous, being an integral part of IFNR-αIFNR-γ,IL-2Rβ, IL-6R and CNTFR signaling (Muller et Nature, 366:129-135 (1993);Silvennoinen et al., Nature, 366:583-585 (1993); Stahl et al., Science,263:92-95 (1994), Tanaka et al., Proc. Natl. Acad. Sci., 91:7271-7275(1994)). Tyk2, which may also be employed as a PSD, is involved withIFN-α, IL-6, IL-12, and CNTF induced signaling (Velazquez et al., Cell.70:313-322 (1992); Silvennoinen et al., Nature, 366:583-585 (1993);Stahl et al., Science, 263:92-95 (1994); Colamonici et al., J. Biol.Chem, 269:3518-3522 (1994); Darnell et al., Science, 264:1415-1421(1994), Bacon et al., J. Exp. Med., 181:399-404 (1995)) and is found inboth hematopoietic and non-hematopoietic tissues (Firmbach-Kraft et al.,Oncogene 5: 1329-1336, 1990). In addition to the Janus kinases describedabove, a new JAK kinase Ptk-2 has recently been described in embryonichippocampal neurons (Sanchez et al. Proc. Natl. Acad. Sci., 91:1819-1823(1994), and can be used to form the proliferation signaling domain ofany of the chimeric proliferation receptor proteins of the presentinvention.

One may introduce the CPR into cells where the PSD being used is notnaturally found in those cells or is part of a pathway which isordinarily not active in those cells. This unnatural expression of aparticular Janus kinase or cytokine receptor subunit may have addedutility. For example, if the PSDs are more active in this unnaturallocation, they may be more efficient stimulators of proliferation.Alternatively, if the PSDs are less active in the unnatural locationthey may be less likely to be constitutively active and thus moreresponsive to an inducer.

The transmembrane domain may be contributed by the protein contributingthe proliferation signaling portion, the protein contributing theextracellular inducer clustering domain, or by a totally differentprotein. For the most part it will be convenient to have thetransmembrane domain naturally associated with one or the other of theother domains. In some cases it will be desirable to employ thetransmembrane domain of the ζ, η or FcεR1γ chains or related proteinswhich contain a cysteine residue capable of disulfide bonding, so thatthe resulting chimeric protein will be able to form disulfide linkeddimers with itself, or with unmodified versions of the ζ, η or FcεR1γchains or related proteins. In some instances, the transmembrane domainwill be selected or modified by amino acid substitution to avoid bindingof such domains to the transmembrane domains of the same or differentsurface membrane proteins to minimize interactions with other members ofthe receptor complex. In other cases it will be desirable to employ thetransmembrane domain of ζ, η, FcεR1-γ and -β, MB1 (Ig α), B29 (Igβ),Bovine Leukemia Virus gp30 (BLV gp30), or CD3-γ, δ, or ε, in order toretain physical association with other members of the receptor complex.

The CPRs of the present invention may be designed so as to avoidinteraction with other surface membrane proteins native to the targethost. In order to achieve this, one may select for a transmembranedomain which is known not to bind to other transmembrane domains, or onemay modify specific amino acids, e.g. substitute for a cysteine, or thelike.

The extracellular inducer-responsive clustering domain (ECD) may beobtained from any of the wide variety of extracellular domains ofeukaryotic transmembrane proteins, secreted proteins or other proteinsassociated with ligand binding and/or signal transduction. The ECD maybe part of a protein which is monomeric, homodimeric, heterodimeric, orassociated with a larger number of proteins in a non-covalent ordisulfide-bonded complex.

In particular, the ECDs may consist of monomeric or dimericimmunoglobulin molecules, or portions or modifications thereof, whichare prepared in the following manner.

The full-length IgG heavy chain comprising the VH, CH1, hinge, and theCH2 and CH3 (Fc) Ig domains is fused to the proliferation signalingdomain (PSD) via the appropriate transmembrane domain. If the VH domainalone is sufficient to confer antigen-specificity (so-called"single-domain antibodies"), homodimer formation of the Ig-PSD chimerais expected to be functionally bivalent with regard to antigen bindingsites. If both the VH domain and the VL domain are necessary to generatea fully active antigen-binding site, both the IgH-PSD molecule and thefull-length IgL chain are introduced into cells to generate an activeantigen-binding site. Dimer formation resulting from the intermolecularFc/hinge disulfide bonds results in the assembly of Ig-PSD receptorswith extracellular domains resembling those of IgG antibodies.Derivatives of this Ig-PSD chimeric receptor include those in which onlyportions of the heavy chain are employed in the fusion. For example, theVH domain (and the CH1 domain) of the heavy chain can be retained in theextracellular domain of the Ig-PSD chimera (VH-PSD), but VH-PSD dimersare not formed. As above, the full-length IgL chain can be introducedinto cells to generate an active antigen-binding site.

As indicated, the ECD may consist of an Ig heavy chain which may in turnbe covalently associated with Ig light chain by virtue of the presenceof the CH1 region, or may become covalently associated with other Igheavy/light chain complexes by virtue of the presence of hinge, CH2 andCH3 domains. The two heavy/light chain complexes may have differentspecificities, thus creating a CPR which binds two distinct antigens.Depending on the function of the antibody, the desired structure and thesignal transduction, the entire chain may be used or a truncated chainmay be used, where all or a part of the CH1, CH2, or CH3 domains may beremoved or all or part of the hinge region may be removed.

Because association of both the heavy and light V domains are requiredto generate a functional antigen binding site of high affinity, in orderto generate a Ig chimeric receptor with the potential to bind antigen, atotal of two molecules will typically need to be introduced into thehost cell. Therefore, an alternative and preferred strategy is tointroduce a single molecule bearing a functional antigen binding site.This avoids the technical difficulties that may attend the introductionand coordinated expression of more than one gene construct into hostcells. This "single-chain antibody" (SAb) is created by fusing togetherthe variable domains of the heavy and light chains using an oligo- orpolypeptide linker, thereby reconstituting an antigen binding site on asingle molecule.

Single-chain antibody variable fragments (SAbFv) in which the C-terminusof one variable domain (VH or VL) is tethered to the N-terminus of theother (VL or VH, respectively), via a oligo- or polypeptide linker, havebeen developed without significantly disrupting antigen binding orspecificity of the binding (Bedzyk et al. (1990) J. Biol. Chem.,265:18615; Chaudhary et al. (1990) Proc. Natl. Acad. Sci., 87:9491). TheSAbFvs used in the present invention may be of two types depending onthe relative order of the VH and VL domains: VH-1-VL or VL-1-VH (where"1" represents the linker). These SAbFvs lack the constant regions (Fc)present in the heavy and light chains of the native antibody. In anotheraspect of the present invention, the SAbFv fragment may be fused to allor a portion of the constant domains of the heavy chain, and theresulting ECD is joined to the PSD via an appropriate transmembranedomain that will permit expression in the host cell. The resulting CPRsdiffer from the SAbFvs, described above, in that upon binding of antigenthey initiate signal transduction via their cytoplasmic domain.

To aid in the proper folding and efficient expression of the CPRs, theantibody-derived ECDs may be connected at their C-terminal end to one ofa number of membrane hinge regions which are a normal part ofmembrane-bound immunoglobulin molecules. For example, the eighteen aminoacids of the IGHG3 M1 exon may be used (Bensmana and Lefranc,Immunogenet., 32:321-330 (1990)). The TM domain is attached to theC-terminal end of the membrane hinge. It is also contemplated thatmembrane hinge sequences may be used to connect non-antibody derivedECDs to the transmembrane domains to increase CPR expression.

Diabodies may also be used as ECDs in the present invention. Diabodiescontain two chimeric immunoglobulin chains, one of which comprises a VHdomain connected to a VL domain on the same polypeptide chain (VH-VL). Alinker that is too short to allow pairing of the VH and VL domains onthis chain with each other is used so that the domains will pair withthe complementary VH and VL domains on the other chimeric immunoglobulinchain to create two antigen-binding sites (Holliger et al., Proc. Natl.Acad. Sci. 90:6444-6448 (1993)). As described above, one of these chainsis linked to the membrane hinge and/or the TM domain, which in turn islinked to the PSD and/or ESD. The other chain (not connected to a PSD)will be co-expressed in the same cell to create a CPR with a diabody ECDwhich will respond to two different extracellular inducer molecules.

Various naturally occurring receptors may also be employed as ECDs,where the receptors are surface membrane proteins, including celldifferentiation antigens such as CD4 and CD8, cytokine or hormonereceptors or cell adhesion molecules. The receptor may be responsive toa natural ligand, an antibody or fragment thereof, a synthetic molecule,e.g., drug, or any other agent which is capable of inducing a signal. Inaddition, either member of a inducer/receptor pair, where one isexpressed on a target cell such as a cancer cell, a virally infectedcell or an autoimmune disease causing cell, may also be used as an ECDin the present invention. In addition, the receptor-binding domains ofsoluble protein ligands or portions thereof could be employed as ECDs inthe CPRs of the present invention. In addition, for example, bindingportions of antibodies, cytokines, hormones, or serum proteins can beused. In addition, the soluble components of the cytokine receptors suchas IL-6R, IL-4R, and IL-7R can be used (Boulay and Paul Current Biology3: 573-581, (1993)).

"Hybrid" ECDs can also be used in the present invention. For example,two or more antigen-binding domains from antibodies of differentspecificities, two or more different ligand-binding domains, or acombination of these domains can be connected to each other by oligo- orpolypeptide linkers to create multispecific extracellular bindingdomains. These ECDs can be used to create CPRs of the present inventionwhich will respond to two or more different extracellular inducermolecules. (See FIG. 1(a)-(c) and (1)-(s) that illustrate the aboveembodiment).

Where a receptor is a molecular complex of proteins, where only onechain has the major role of binding to the ligand, it will usually bedesirable to use solely the extracellular portion of the ligand bindingprotein. Where the extracellular portion may complex with otherextracellular portions of other proteins or form covalent bondingthrough disulfide linkages, one may also provide for the formation ofsuch dimeric or multimeric extracellular regions. Also, where the entireextracellular region is not required, truncated portions thereof may beemployed, where such truncated portion is functional. In particular,when the extracellular region of CD4 is employed, one may use only thosesequences required for binding of gp120, the HIV envelope glycoprotein.In the case in which Ig is used as the extracellular region, one maysimply use the antigen binding regions of the antibody molecule anddispense with the constant regions of the molecule (for example, the Fcregion consisting of the CH2 and CH3 domains).

In some instances, a few amino acids at the joining region of thenatural protein domain may be deleted, usually not more than 30, moreusually not more than 20. Also, one may wish to introduce a small numberof amino acids at the borders, usually not more than 30, more usuallynot more than 20. The deletion or insertion of amino acids will usuallybe as a result of the needs of the construction, providing forconvenient restriction sites, ease of manipulation, improvement inlevels of expression, proper folding of the molecule or the like. Inaddition, one may wish to substitute one or more amino acids with adifferent amino acid for similar reasons, usually not substituting morethan about five amino acids in any one domain. The PSD, ECD, EPSD andICD will generally be from about 50 to 1500 amino acids, depending uponthe particular domain employed, while the transmembrane domain willgenerally have from about 20 to 35 amino acids.

Normally, the signal sequence at the 5' terminus of the open readingframe (ORF) which directs the chimeric protein to the surface membranewill be the signal sequence of the ECD. However, in some instances, onemay wish to exchange this sequence for a different signal sequence.However, since the signal sequence will be removed from the proteinduring processing, the particular signal sequence will normally not becritical to the subject invention.

Extracellular inducers of the present invention can be antigens whichbind the ECDs, described above. These may include viral proteins, (e.g.gp120 and gp41 envelope proteins of HIV, envelope proteins from theHepatitis B and C viruses, the gB and other envelope glycoproteins ofhuman cytomegalovirus, the envelope proteins from the Kaposi'ssarcoma-associated herpesvirus), and surface proteins found on cancercells in a specific or amplified fashion, (eg the IL-14 receptor, CD19and CD20 for B cell lymphoma, the Lewis Y and CEA antigens for a varietyof carcinomas, the Tag72 antigen for breast and colorectal cancer, EGF-Rfor lung cancer, and the HER-2 protein which is often amplified in humanbreast and ovarian carcinomas). For other receptors, the receptors andligands of particular interest are CD4, where the ligand is the HIVgp120 envelope glycoprotein, and other viral receptors, for exampleICAM, which is the receptor for the human rhinovirus, and the relatedreceptor molecule for poliovirus.

The intracellular clustering domain (ICD) can be obtained from theinducer binding domains of a variety of intracellular proteins. Forexample, eukaryotic steroid receptor molecules can be used as ICDs (e.g.the receptors for estrogen. progesterone, androgens, glucocorticoids,thyroid hormone, vitamin D, retinoic acid, 9-cis retinoic acid andecdysone). In addition, variants of steroid and other receptors whichfail to bind their native inducer, but still bind to an antagonist, canbe prepared by one skilled in the art and used to make the CPRs of thisinvention. For example, a C-terminal deletion mutant of the humanprogesterone receptor, which fails to bind progesterone, can beclustered by the addition of progesterone antagonists, including RU 486(Wang et al., Proc Natl Acd Sci 91: 8180-8184, 1994). Binding domainsfrom the eukaryotic immunophilin family of molecules may also be used asICDs. Examples include but are not limited to members of the cyclophilinfamily: mammalian cyclophilin A, B and C, yeast cyclophilins 1 and 2,Drosophila cyclophilin analogs such as ninaA; and members of the FKPBfamily: the various mammalian isoforms of FKBP and the FKBP analog fromNeurospora (Schreiber, Science, 251:283-287 (1991), McKeon, Cell,66:823-826, (1991), Friedman and Weissman, Cell, 66:799-806, (1991), Liuet al., Cell, 66:807-815 (1991)). For example, the inducer bindingportion of the immunophilin, FKBP12, which can be clustered in thecytoplasm by the addition of FK1012, a synthetic dimeric form of theimmunosuppressant FK506 (Spencer et al., Science 262:1019-1024 (1993)can be used as an ICD.

The intracellular inducers of the present invention must be moleculeswhich can be delivered to the cytoplasm. For example, the inducer may belipophilic, or be transported into the cell by active transport orpinocytosis, by fusion with a liposome carrying the inducer, or bysemi-permeabilization of the cell membrane. The intracellular inducerscluster the ICDs which make up the CIPRs of the present invention.Examples of inducers include, but are not limited to synthetic dimericmolecules such as FK1012 (Spencer et al., Science, 262:1019-1024 (1993))or dimeric derivatives of the binding domains of other immunophilinbinding molecules such as cyclosporin, rapamycin and 506BD (Schreiber,Science, 251:283-287 (1991), McKeon, Cell, 66:823-826, (1991)).Steroids, such as estrogen, progesterone, the androgens,glucocorticoids, thyroid hormone, vitamin D, retinoic acid, 9-cisretinoic acid or ecdysone, or antagonists or derivatives of thesemolecules may also be used as intracellular inducer molecules. Inparticular the steroid antagonist RU 486 may be used (Wang et al., Proc.Natl. Acad. Sci., 91:8180-8184 (1994)).

The effector function signaling domains (EFSDs) employed in the presentinvention may be derived from a protein which is known to activatevarious second messenger pathways. One pathway of interest is thatinvolving phosphatidylinositol-specific phospholipase hydrolysis ofphosphatidylinositol-4,5-biphosphate, and production ofinositol-1,4,5-trisphosphate and diacyl glycerol. The calcium mediatedpathway, the tyrosine and serine/threonine kinase and phosphatasepathway, the adenylate cyclase, and the guanylate cyclase pathways mayalso be second messenger pathways. EFSDs of interest include proteinswith ARAM motifs (Reth, Nature, 338:383-384 (1989), Weiss, Cell,73:209-212, (1993)), for example, the ζ chain of the T-cell receptor,the η chain, which differs from the ζ chain only in its most C-terminalexon as a result of alternative splicing of the ζ mRNA, the γ and βsubunits of the FcεR1 receptor, the MB1 (Igα) and B29 (Igβ) chains ofthe B cell receptor, the BLV gp30 protein and the δ, γ, and e chains ofthe T-cell receptor (CD3 chains), other protein homologous to the aboveprotein subunits including synthetic polypeptides with ARAM motifs, andsuch other cytoplasmic regions which are capable of transmitting asignal as a result of interacting with other proteins capable of bindingto a inducer (Romeo et al., Cell, 68:889-897 (1992); Weiss, Cell,73:209-212 (1993)). The syk family of tyrosine kinases may also be usedas effector function signaling domains. The clustering of these domainsfrom Syk and ZAP-70 leads to the activation of T cell cytolytic activity(Kolanus et al., Cell, 74:171-183 (1993)). In addition, the src familyof tyrosine kinases (Lck, Fyn, Lyn, etc. (Rudd et al., Immunology Today,15:225-234 (1994)) and molecules involved in T cell transduction may beused as EPSDs in the present invention. A number of EFSDs or functionalfragments or mutants thereof may be employed, generally ranging fromabout 50 to 1500 amino acids each, where the entire naturally occurringcytoplasmic region may be employed or only an active portion thereof.

The CPRs of the present invention are employed in a wide variety oftarget host cells, normally cells from vertebrates, more particularly,mammals, desirably domestic animals or primates, particularly humans. Inparticular, the subject invention may also find application in theexpansion of lymphoid cells, e.g., T lymphocytes, B lymphocytes,cytotoxic lymphocytes (CTL), natural killer cells (NK),tumor-infiltrating-lymphocytes (TIL) or other cells which are capable ofkilling target cells when activated. In addition, suitable host cells tointroduce CPRs of the present invention include hematopoietic stemcells, which develop into cytotoxic effector cells with both myeloid andlymphoid phenotype including granulocytes, mast cells, basophils,macrophages, natural killer INK) cells and T and B lymphocytes. Inparticular, diseased cells, such as cells infected with HIV, HTLV-I orII, cytomegalovirus, hepatitis B or C virus, Mycobacterium avium, etc.,neoplastic cells, or autoimmune disease-causing cells where the diseasedcells have a surface marker associated with the diseased state may bemade specific targets of the cells expressing the CPRs of the presentinvention. In the present invention, a cell may express dual CEFR andCPR receptors, which contain the same extracellular binding domain (eg.CD4), or a cell may express a hybrid chimeric receptor combining bothsignaling domains (EFSD and PSD). In each case, the binding of oneinducer to the extracellular binding domain will stimulate cells to actas therapeutic agents at the same time they are expanding in response tobinding to inducer, e.g., gp120 for HIV or cancer-specific antigens.

In a preferred embodiment, the present invention relates to the designof chimeric proliferation receptor (CPR) molecules which can endow Tcells with the ability to proliferate in an antigen-specific and IL-2independent manner. A T cell ordinarily requires as many as threedistinct stimuli to become fully activated and begin to proliferate. Itmust receive two signals from the antigen presenting cell (APC). Thefirst of these signals occurs upon engagement of the T cell antigenreceptor with the peptide antigen-MHC complex. The second costimulatorysignal is provided through the interaction of the CD28 or CTLA4 proteinson the T cell surface with either the B7-2 or B7 proteins, theircounterreceptors on the APC (Clark and Ledbetter, Nature, 367:425-428(1994); Croft, Current Opinion in Immunology, 6:431-437 (1994)). Inaddition to these two signals provided during cell to cell contactbetween the T cell and APC, it is apparent that certain cytokines, forexample IL-2, play an important role in initiating and sustainingongoing proliferation of activated T cells (Taniguchi and Minami, Cell,73:5-8 (1993)). The antigen receptor-mediated signal (e.g., anti-CD3MAb) and the costimulatory signal (e.g., APC) play an important role ininitiating and sustaining T cell proliferation, for example, by inducingIL-2 receptors which will in turn make the T cell responsive toautocrine or exogenous IL-2 stimulation. Chimeric proliferationreceptors for T cells can route an antigen signal directly through theIL-2 signaling apparatus, and bypass the need to engage the T cellreceptor and costimulatory receptor to elicit T cell proliferation,while still maintaining antigen specificity. This chimeric receptor willlink an ECD which is an antigen binding moiety such as an antibody or aviral receptor (e.g., CD4, the receptor for HIV) to a proliferationsignaling domain which is a component of the IL-2R. One embodiment ofthe CPR invention would be to use one of the subunits of the IL-2receptor (IL-2R) as a proliferation signaling domain. Specifically, theβ and γ chains of the IL-2R may be utilized as PSDs in the presentinvention. Alternatively, the CPRs may incorporate both of all or partof the transducing domains of the IL-2Rβ and γ, which are connectedthrough the use of an appropriate polypeptide linker sequence, in asingle chimeric receptor. In a further embodiment, the CPR containingthe IL-2Rβ PSD or the IL-2Rγ PSD alone is complemented with the nativeform of IL-2R γ or IL-2Rβ subunit respectively, which is provided bytransduction. It is further contemplated that the signal transducingdomains of the cytokine receptor superfamily described above mayfunction as the PSDs in the CPRs in T cells of the present invention. Ina further embodiment, chimeric proliferation receptors may incorporatemore than one signaling domain chosen from the cytokine receptor family,which may be connected through an appropriate oligo- or polypeptidelinker sequence in a single chimeric receptor.

In another preferred embodiment, the present invention relates to theuse of chimeric proliferation receptors to induce the proliferation of Tcells, where the proliferation signaling domains are comprised of one ormore of the family of Janus kinases, i.e., JAK1, JAK2, JAK3, Tyk2 andPtk-2. In the most preferred embodiment, either JAK1 or JAK3 alone ortogether may be employed as the PSD(s) since they play a critical rolein IL-2 induced proliferation of T cells: The kinase activity of bothJAK1 and JAK3 becomes stimulated after IL-2 binding to the IL2R. JAK1and JAK3 are associated with the membrane proximal regions of the IL-2Rβand γ chains, respectively, which are integral to the transmission ofproliferative stimuli (Asao et al., FEBS Letters, 351:201-206 (1994);Johnston et al., Nature, 370:151-153 (1994); Miyazaki et al., Science,266:1045-1047 (1994); Russell et al., Science, 366:1042-1044 (1994);Witthuhn et al., Nature, 370:153-157 (1994)). However, as discussedabove, a Janus kinase or cytokine receptor family subunit which is notnaturally found or used in a given cell may be of particular utility asa PSD, in that such a molecule may either have greater kinase activityand thus be more efficient at promoting cell growth, or it may have lessconstitutive activity and thus be more readily modulated by clustering.

In yet another preferred embodiment, the present invention relates to Tcells containing single chimeric polypeptide receptors that drive bothproliferation and effector function through the same inducer molecule.Thus, the extracellular inducer-responsive clustering domain is linkedvia a transmembrane domain to two signal transducing domains in tandem.One signal transducing domain contains the proliferation signal (asdescribed above) while the other signal transducing domain contains aneffector function signal. In a particularly preferred embodiment, theeffector signaling domain from a member of the Syk tyrosine kinasefamily which activates cytolysis, Syk or ZAP-70, is in a chimericreceptor with a proliferation signaling domain from a Janus kinase,JAK1, JAK2, JAK3, Tyk2 or Ptk-2.

In another particularly preferred embodiment, the effector functionsignaling domain from ζ, η, the FcεR1-β and -γ chains, MB1 (Igα) and B29(Igβ), BLV gp30, or the CD3γ, δ and 68 chains, which also activatescytolysis, is in a chimeric receptor with a proliferation signalingdomain from a Janus kinase, JAK1, JAK2, JAK3, Tyk2 or Ptk-2 or acytokine receptor subunit. These hybrid receptors are contemplated toinduce not only antigen-specific proliferation, but the activation ofantigen-specific cytotoxic or helper effector function activity as well.

In yet another preferred embodiment, the present invention relates toengineered T cells expressing CPRs which already contain a chimericeffector function receptors. These dual chimera receptor-expressing Tcells respond to specific antigen by activating cytolytic or helpereffector function, and may respond to the same or a different antigen byproliferating as well. It is thus desirable to engineer a T cell so thatit can become activated to proliferate at the disease site, as well asto kill its target, in a manner dependent only upon the presence of theappropriate antigen-expressing cell. In this preferred embodiment, thetwo chimeric receptors are provided to the cell as separate molecules.As an example, chimeric proliferation receptors which contain an ECDwhich recognizes HIV antigens are introduced into cytotoxic T cellsexpressing a chimeric effector function receptor which contains an ECDwhich recognizes the same or different HIV antigens. This will allowboth the proliferation of and cytotoxic actions of the engineered cellsupon contact with HIV infected cells, even in the absence of IL-2.

The chimeric construct, which encodes the chimeric protein according tothis invention will be prepared in conventional ways. Since, for themost part, natural sequences may be employed, the natural genes may beisolated and manipulated, as appropriate, so as to allow for the properjoining of the various domains. Thus, one may prepare the truncatedportion of the sequence by employing the polymerase chain reaction(PCR), using appropriate primers which result in deletion of theundesired portions of the gene. Alternatively, one may use primerrepair, where the sequence of interest may be cloned in an appropriatehost. In either case, primers may be employed which result in termini,which allow for annealing of the sequences to result in the desired openreading frame encoding the chimeric protein. Thus, the sequences may beselected to provide for restriction sites which are blunt-ended, or havecomplementary overlaps.

If desired, the extracellular domain may also include thetranscriptional initiation region, which will allow for expression inthe target host. Alternatively, one may wish to provide for a differenttranscriptional initiation region, which may allow for constitutive orinducible expression, depending upon the target host, the purpose forthe introduction of the subject chimeric protein into such host, thelevel of expression desired, the nature of the target host, and thelike. Thus, one may provide for expression upon differentiation ormaturation of the target host, activation of the target host, or thelike.

A wide variety of promoters have been described in the literature, whichare constitutive or inducible, where induction may be associated with aspecific cell type or a specific level of expression. Alternatively, anumber of viral promoters are known which may also find use. Promotersof interest include the β-actin promoter, SV40 early and late promoters,immunoglobulin promoter, human cytomegalovirus promoter, and the Friendspleen focus-forming virus promoter. The promoters may or may not beassociated with enhancers, where the enhancers may be naturallyassociated with the particular promoter or associated with a differentpromoter.

The sequence of the open reading frame may be obtained from genomic DNA,cDNA, or be synthesized, or combinations thereof. Depending upon thesize of the genomic DNA and the number of introns, one may wish to usecDNA or a combination thereof. In many instances, it is found thatintrons stabilize the mRNA. Also, one may provide for non-coding regionswhich stabilize the mRNA.

A termination region will be provided 3' to the cytoplasmic domain,where the termination region may be naturally associated with thecytoplasmic domain or may be derived from a different source. For themost part, the termination regions are not critical and a wide varietyof termination regions may be employed without adversely affectingexpression.

The various manipulations may be carried out in vitro or may beintroduced into vectors for cloning in an appropriate host, e.g., E.coli. Thus, after each manipulation, the resulting construct fromjoining of the DNA sequences may be cloned into an expression vector.The sequence may be screened by restriction analysis, sequencing, or thelike to insure that it encodes the desired chimeric protein.

The chimeric construct may be introduced into the target cell in anyconvenient manner. Techniques include calcium phosphate or DEAE-dextranmediated DNA transfection, electroporation, protoplast fusion, liposomefusion, biolistics using DNA-coated particles, and infection, where thechimeric construct is introduced into an appropriate virus (egretrovirus, adenovirus, adeno-associated virus, Herpes virus, Sindbisvirus, papilloma virus), particularly a non-replicative form of thevirus, or the like. In addition, direct injection of naked DNA orprotein- or lipid-complexed DNA may also be used to introduce DNA intocells.

Once the target host has been transformed, integration will usuallyresult. However, by appropriate choice of vectors, one may provide forepisomal maintenance. A large number of vectors are known which arebased on viruses, where the copy number of the virus maintained in thecell is low enough to maintain the viability of the cell. Illustrativevectors include SV40, EBV and BPV.

It is also contemplated that the introduction of the chimeric constructsof the present invention into cells may result in the transientexpression of the CPRs. Such transient expression may be preferable if ashort-term therapeutic effect is desired. Unstable replication or theabsence of DNA replication may result, for example, from adenovirusinfection or transformation with naked DNA.

Once one has established that the transformed host cell expresses theCPR of the present invention in accordance with the desired regulationand at a desired level, one may then determine whether the CPR isfunctional in the host cell in providing for the desired proliferationsignal. One may use established methodology for measuring proliferationto verify the functional capability of the CPR. The proliferativeresponse of cells can be measured by a variety of techniques known tothose skilled in the art. For example, DNA synthesis can be measured bythe incorporation of either tritiated thymidine or orotic acid. Theincorporation of bromodeoxyuridine into newly synthesized DNA can bemeasured by immunological staining and the detection of dyes, or byELISA (Enzyme-linked immunosorbent assay) (Doyle et al., Cell and TissueCulture: Laboratory Procedures, Wiley, Chichester, England, (1994)). Themitotic index of cells can be determined by staining and microscopy, bythe fraction labeled mitoses method or by FACS analysis (Doyle et al.,supra, (1994); Dean, Cell Tissue Kinet. 13:299-308 (1980); Dean, CellTissue Kinet. 13:672-681 (1980)). The increase in cell size whichaccompanies progress through the cell cycle can be measure bycentrifugal elutriation (Faha et al., J Virol. 67:2456-2465 (1993)).Increases in the number of cells may also be measured by counting thecells, with or without the addition of vital dyes. In addition, signaltransduction can also be measured by the detection of phosphotyrosine,the in vitro activity of tyrosine kinases from activated cells, c-mycinduction, and calcium mobilization as described in the Examples infra.

As described previously in the specific embodiments, the subject CPRsmay be used to direct the proliferation of immune cells with effectorfunction. The CPRs may be introduced into cells that already contain achimeric receptor construct that stimulates effector function uponcontact with a target inducer. The two chimeric constructs may respondto the same or different inducers. Alternatively, a hybrid CPR may beused which contains both a proliferation signaling domain and aneffector function signaling domain. These cells would respond to asingle target inducer by proliferating and by expressing effectorfunction. Thus, these lymphocytes can be activated by any group of cellswhich contain specific membrane proteins or antigens which may bedistinguished from the membrane proteins or antigens on normal cells.For example, neoplastic cells, virus-infected cells, parasite-infectedcells, or any other diseased cells would be targets for CEPR-containinglymphocytes.

Among the lymphocytes which can be used to treat human disease arecytotoxic CD8+ T cells (CTLs) which have been engineered with CEPRscontaining ECDs which recognize specific antigens and can be used tokill infected cells in a variety of viral, and parasitic diseases, wherethe infected cells express the antigens from the pathogen. Inparticular, CEPR-CTLs would be particularly effective against viraldiseases where transplanted autologous CTLs have shown some efficacy,such as CMV (Reusser et al, Blood, 78:1373-1380 (1991), Riddell et al.,Science, 257:238-241 (1992)) or where explanted and expanded CTLscontinued to have cytolytic activity against virally infected cells,such as HIV (Lieberman et al, Aids Res. and Human Retroviruses,11:257-271 (1995)). These CEPRs can be constructed with ECDs whichrecognize the vital envelope proteins. For example, SAbs which recognizeeither gp120 or gp41, or the CD4 extracellular domain which recognizesgp120 can be used to engineer HIV-specific CTLs. CEPR-CTLs can also beengineered for use against other viruses, such as Hepatitis B virus,Hepatitis C virus, Kaposi's sarcoma associated Herpes virus, the HerpesSimplex viruses, Herpes Zoster virus, and papilloma viruses. Anothertarget for the engineered CTLs are neoplastic cells which expresscancer-specific neoantigens or over-express specific membrane proteins.Examples include the IL-14 receptor, CD19 and CD20 for B cell lymphoma,the Lewis Y and CEA antigens for a variety of carcinomas, the Tag72antigen for breast and colorectal cancer, EGF-R for lung cancer, and theHER-2 protein which is often amplified in human breast and ovariancarcinomas. As an example, human Heregulin (Hrg), a protein similar instructure to Epidermal Growth Factor (EGF), has been identified as aligand for the HER-2 protein (Holmes et al., Science (1992)256:1205-1210). The extracellular domain of Hrg could be used as an ECDto form a chimeric construct of the present invention to direct T cellsto kill breast carcinoma cells. CEPR-CTLs can also be used to targetautoimmune cells in the treatment of autoimmune diseases such asSystemic Lupus Erythematosis (SLE), myasthenia gravis, diabetes,rheumatoid arthritis, and Grave's disease.

CD4⁺ helper T cells (THs) engineered with CEPRs containing ECDs whichrecognize specific antigens can also be used to treat human disease. Inparticular, lymphokine production by CEPR-THs may be effective againstcancer cells and mycobacterial infections, including Mycobacteriumavium, Mycobacterium tuberculosis and Mycobactium leprae.

Chimeric proliferation receptors which do not contain effector functionsignaling domains may also be of use in the treatment of human disease.Various cell types containing the CPR constructs described above may begrown in an appropriate nutrient medium for expansion or may be expandeddirectly in the body via signaling through the CPR, depending on thecell type, and used in a variety of ways. For example, the expandedcells may be used to reconstruct existing tissue or provide new tissuein transplantation therapy. In a particular example, keratinocytes, usedfor replacement of skin in the case of burns, may be grown to form acontinuous layer prior to application. Alternatively, the keratinocytesmay be used in the case of plastic surgery to replace skin removed fromthe host for use at another site.

Other cell types that would be of particular interest for expansionafter delivery of the CPRs of the subject invention are islets ofLangerhans which may be grown and introduced into a host by capsules orother means, for the production of insulin. Retinal epithelial cells mayalso be expanded and injected or implanted into the subretinal space ofthe eye to treat visual disorders, such as macular degeneration. Immunecells, described in detail above, may be expanded ex vivo and injectedinto the bloodstream or elsewhere to treat immune deficiency. Myoblastsmay be expanded with the present invention and injected at various sitesto treat muscle wasting diseases such as Duchenne muscular dystrophy.Hepatocytes may be expanded for use in liver regeneration. Endothelialcells may also be expanded to repair blood vessels or to deliverproteins to the circulation. Nerve cells which ordinarily do notproliferate may be targets for expression by using the CPRs of presentinvention. In addition cells which will not proliferate in vitro, andtherefore cannot be manipulated or genetically engineered may be idealrecipients of the CPRs of the present invention.

Additional types of cells that would benefit from the subject CPRconstructs include cells that have genes previously introduced orsimultaneously introduced with a CPR which may serve in proteinproduction or to correct a genetic defect. Production of proteins mayinclude growth factors, such as, erythropoietin, G-CSF, M-CSF, andGM-CSF, epidermal growth factor, platelet derived growth factor, humangrowth factor, transforming growth factor, etc; lymphokines, such as theinterleukins; hormones, such as ACTH, somatomedin, insulin, angiotensin,etc.; coagulation factors, such as Factor VIIIC; deoxyribonuclease fortreating cystic fibrosis; glucocerebrosidase for treating Gaucher'sdisease; normal versions of proteins associated with genetic diseasessuch as adenosine deaminase or the CFTR protein associated with cysticfibrosis; protective agents, such as α1-antitrypsin; regulatory proteinsor enzymes associated with the production of amino acid free products,such as the expression of tyrosine hydroxylase for the production ofL-dopamine, and the like.

The recipient of genetically modified allogeneic cells can beimmunosuppressed to prevent the rejection of the transplanted cells. Inthe case of immunocompromised patients, no pretransplant therapy may berequired. Another alternative source of cells to be transplanted areso-called "universal donor" cells which have been genetically engineeredso that they do not express antigens of the major histocompatibilitycomplex or molecules which function in antigen presentation.

High-titer retroviral producer lines are used to transduce the chimericproliferation receptor constructs into autologous or allogeneic humanT-cells, hematopoietic stem cells or other cells, described abovethrough the process of retroviral mediated gene transfer as described byLusky et al. in (1992) Blood 80:396. In addition to the gene encodingthe chimeric proliferation receptor, additional genes may be included inthe retroviral construct. These include genes such as the thymidinekinase or cytosine deaminase genes (Borrelli et al. (1988) Proc. Natl.Acad. Sci. USA 85:7572) which acts as a suicide gene for the markedcells if the patient is exposed to gancyclovir or 5'-fluorouracil (5FU),respectively. Thus, if the percentage of marked cells is too high,gancyclovir or 5FU may be administered to reduce the percentage of cellsexpressing the chimeric receptors. In addition, if the percentage ofmarked cells needs to be increased, the multi-drug resistance gene canbe included (Sorrentino et al. (1992) Science 257:99) which functions asa preferential survival gene for the marked cells in the patients if thepatient is administered a dose of a chemotherapeutic agent such astaxol. Therefore, the percentage of marked cells in the patients can betitrated to obtain the maximum therapeutic benefit.

In addition, high-titer adenoviral producer lines may be used totransduce the chimeric proliferation receptor constructs into autologousor allogeneic nerve cells, hematopoietic cells including stem cells,islets of Langerhans, keratinocytes, muscle cells or other cellsfollowing the methods of adenoviral mediated gene transfer as describedby Finer et al. in Blood, 83:43-50 (1994). Similar to the proceduredescribed above, other genes may be included in the adenoviralconstructs in addition to the chimeric proliferation receptor in therecipient cell. After introduction of the construct into the cell typeof interest, the cells may be expanded in an appropriate medium wellknow in the art and used in a variety of ways previously described.

The following examples are by way of illustration and not by way oflimitation.

EXPERIMENTAL EXAMPLE 1 Construction of CPRs comprising a ligand-receptor(CD4) extracellular clustering domain and a Janus kinase or cytokinereceptor subunit proliferation signaling domain.

Expression vectors for CD4-Janus kinase and CD4-cytokine receptorsubunit hybrids were created using pIK1.1F3Sal. This plasmid was made byintroducing a SalI site into pIK1.1F3 (U.S. Pat. No. 5,359,046) whichdirects the expression CD4-ζ, a chimeric protein comprised of the humanCD4 extracellular (EXT) and transmembrane (TM) domains (residues 1 to395 of mature CD4) fused to the cytoplasmic (CYT) domain of human ζ. TheSalI site was introduced by oligonucleotide-directed mutagenesis usingsingle stranded pIK1.1F3 DNA with oligo 1 as the primer. pIK1.1F3Sal wasidentified by restriction analysis and its sequence confirmed by Sangerdideoxynucleotide sequencing. The creation of the SalI site results inthe insertion of an Asp codon at the junction of CD4 TM and ζ CYT, andpermits the replacement of ζ CYT domain with a Janus kinases or cytokinereceptor subunit CYT domain with the retention of a single Asp residueat the junction. Derivatives lacking the extra Asp codon or containingother oligo- or polypeptide linkers are constructed byoligonucleotide-directed mutagenesis (Zoller and Smith, (1982) NucleicAcids Res,. 10:6487-6500). In each example below, the correct expressionplasmid was identified by restriction mapping and its structureconfirmed by DNA sequencing.

a) Construction of CD4-mJAK1

pIKCD4-mJAK1 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) joined at theirC-terminus to the entire mouse JAK1 Janus kinase by an Asp residue. Thisplasmid was constructed from three DNA fragments: 1) a vector fragmentof 5.7 kb obtained by digestion of pIK1.1F3Sal with SalI and ApaI, 2) a2.6 kb fragment encoding the N-terminus of mJAK1 obtained by digestionof pBluescriptKSmJAK1 (provided by James Ihle & Bruce Witthuhn, St JudeChildren's Research Hospital, Memphis, Tenn.) with NcoI and SstI, andligation to a SalI-NcoI adaptor consisting of oligonucleotides 2 & 3(SEQ ID NO: 2 & 3), and 3) a 0.9 kb fragment encoding the C-terminus ofmJAK1 obtained by digestion of pBluescriptKSmJAK1 with SstI and NdeI,and ligation to an NdeI-ApaI adaptor consisting of oligonucleotides 4 &5 (SEQ ID NO: 4 & 5).

b) Construction of CD4-mJAK2

pIKCD4-mJAK2 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1-395) joined at their C-terminusto the entire mouse JAK2 Janus kinase by an Asp residue. This plasmidwas constructed in two steps. First, an intermediate plasmid wasconstructed from two DNA fragments: 1) a vector fragment of 5.7 kbobtained by digestion of pIK1.1F3Sal with SalI and ApaI and modificationof the cohesive ends with T4 polymerase and dNTPs to create blunt ends,and 2) a 3.7 kb fragment encoding the entire mJAK2 protein obtained bydigestion of pBluescriptSKmJAK2 (provided by James Ihle & BruceWitthuhn, St Jude Children's Research Hospital, Memphis, Tenn.) withNotI and NheI and extension of the cohesive ends with T4 polymerase anddNTPs to create blunt ends. A clone with the insert in the correctorientation, having the blunted SalI and NotI sites joined, wasidentified and used to prepare a single-stranded DNA template. Secondly,this template was used for oligonucleotide-directed mutagenesis witholigonucleotide 6 (SEQ ID NO:6) as a primer to fuse amino acid 1 ofmJAK2 in-frame to the Asp residue following the CD4 TM region. Thecorrect expression plasmid was identified by colony hybridization usingoligonucleotide 7 (SEQ ID NO:7) as a probe.

c) Construction of CD4-mJAK3

pIKCD4-mJAK3 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1-395) joined at their C-terminusto the entire mouse JAK2 Janus kinase by an Asp residue. This plasmidwas constructed from three DNA fragments: 1) a vector fragment of 5.7 kbobtained by digestion of pIK1.1F3Sal with SalI and ApaI, 2) a 1.3 kbfragment encoding the mJAK3 N-terminus obtained by digestion ofpBluescriptSKmJAK3 (provided by James Ihle & Bruce Witthuhn, St JudeChildren's Research Hospital, Memphis, Tenn.) with Eco47III and EcoRI,and ligation to a Sal I-Eco47III adaptor consisting of oligonucleotides8 a 9 (SEQ ID NO:8 & 9), and 3) a 2.2 kb fragment encoding the mJAK3C-terminus obtained by digestion of pBluescriptSKmJAK3 with EcoRI andBamHI, and ligation to a BamHI-ApaI adaptor consisting ofoligonucleotides 10 & 11 (SEQ ID NO: 10 & 11).

d) Construction of CD4-hTyk2

pIKCD4-hTyk2 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1-395) joined at their C-terminusto the entire human Tyk2 Janus kinase by an Asp residue. This plasmidwas constructed in two steps. First, an intermediate plasmid wasconstructed from three DNA fragments: 1) a vector fragment of 5.7 kbobtained by digestion of pIK1.1F3Sal with SalI, extension of thecohesive end with T4 polymerase and dNTPs to create a blunt end,followed by digestion with ApaI, and 2) a 1.1 kb fragment encoding theN-terminus of hTyk2 obtained by digestion of pRCFwt (provided by SandraPellegrini, Institut Pasteur, Paris) with SphI, extension of thecohesive end with T4 polymerase and dNTPs, followed by digestion withSacII, and 3) a 2.6 kb fragment encoding the C-terminus of hTyk2obtained by digestion of pRCFwt with SacII and ApaI. Secondly, asingle-stranded DNA template was prepared from this intermediate plasmidand used for oligonucleotide-directed mutagenesis with oligonucleotide12 (SEQ ID NO: 12) as a primer to fuse amino acid 1 of hTyk2 in-frame tothe Asp residue following the CD4 coding region. The correct expressionplasmid was identified by colony hybridization using oligonucleotide 13(SEQ ID NO:13)as probe.

e) Construction of CD4-hJAK3

pIKCD4-hJAK3 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1-395) joined at their C-terminusto the entire human Tyk2 Janus kinase by an Asp residue. This plasmidwas constructed in two steps. First, an intermediate plasmid wasconstructed from three DNA fragments: 1) a vector fragment of 5.7 kbobtained by digestion of pIK1.1F3Sal with SalI and ApaI, and extensionof the cohesive ends with T4 polymerase and dNTPs to create blunt ends,and 2) a 3.6 kb fragment encoding the entire hJAK3 protein obtained bydigestion of pBluescriptSKhJAK3 (provided by John O'Shea, NationalCancer Institute, Frederick, Md.) with EcoRI and NdeI and extension ofthe cohesive ends with T4 polymerase and dNTPs to create blunt ends. Aclone with the insert in the correct orientation, having the bluntedSalI and EcoRI sites joined, was identified and used to prepare asingle-stranded DNA template. Secondly, this template was used foroligonucleotide-directed mutagenesis with oligonucleotide 14 (SEQ IDNO:14)as a primer to fuse amino acid 1 of hJAK3 in-frame to the Aspresidue following the CD4 TM region. The correct expression plasmid wasidentified by colony hybridization using oligonucleotide 15 (SEQ IDNO:15)as a probe.

f) Construction of CD4-hIL2Rβ

pIKCD4-hIL2Rβ directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1-395) joined at their C-terminusto the CYT domain of the human IL-2 receptor β subunit (residues 240-525of the mature polypeptide) by an Asp residue. This plasmid wasconstructed from two DNA fragments: l ) a vector fragment of 5.7 kbobtained by digestion of pIK1.1F3Sal with ApaI, extension of thecohesive end with T4 polymerase and dNTPs to create a blunt end,followed by digestion with SalI, and 2) a 0.9 kb fragment encoding thehIL-2Rβ CYT domain obtained by digestion of a PCR-generated DNA fragmentwith SalI and EcoRV. The PCR-generated fragment was obtained by 1)isolating mRNA from normal human CD8-positive T cells with a FastTrackkit (Invitrogen, San Diego, Calif.), 2) using the mRNA to preparesingle-stranded cDNA using a cDNA Cycle kit (Invitrogen, San Diego,Calif.) with oligonucleotide 16 (SEQ ID NO:16) as a primer, and 3)amplifying the single-stranded cDNA by PCR using oligonucleotides 17 &18 (SEQ ID NO: 17 & 18) as primers to generate a fragment whichincorporates SalI and EcoRV sites at the 5' and 3' ends, respectively.

g) Construction of CD4-IL2Rγ

pIKCD4-IL2Rγ directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1-395) joined at their C-terminusto the CYT domain of the human IL-2 receptor γ subunit (residues 262-347of the mature polypeptide) by an Asp residue. This plasmid wasconstructed from two DNA fragments: 1) a vector fragment of 5.7 kbobtained by digestion of pIK1.1F3Sal with ApaI, extension of thecohesive end with T4 polymerase and dNTPs to create a blunt end,followed by digestion with SalI, and 2) a 0.3 kb fragment encoding thehIL-2Rγ CYT domain obtained by digestion of a PCR-generated DNA fragmentwith SalI and EcoRV. The PCR-generated fragment was obtained by 1)isolating a hIL-2Rγ cDNA clone from a λ cDNA library made from activatedhuman T cells (Clontech, Palo Alto, Calif.) using oligonucleotides 19 &20 (SEQ ID NO: 19 & 20)as probes, 2) subcloning an EcoRI fragmentcontaining the hIL-2Rγ CYT domain (residues 268-347), 3) using thesubclone DNA to carry out PCR with oligos 21 and 22 as primers togenerate a fragment in which the codons for hIL-2Rγ residues 262-267were recreated, the EcoRI site was removed, and in which SalI and EcoRVsites were incorporated at the 5' and 3' ends, respectively.

EXAMPLE 2 CPRs containing an antibody extracellular clustering domainand a Janus kinase or cytokine receptor subunit proliferation signalingdomain.

Expression vectors for SAb-Janus kinase and SAb-cytokine receptorsubunit hybrids are created by replacing the CD4 EXT domain in CD4-Januskinase and CD4-cytokine receptor subunit hybrids (examples 1a to 1g)with the EXT domain of F15γ2, a single-chain antibody-ζ chimericreceptor, contained in plasmid pRT43.2F15γ2. F15γ2 is comprised of (fromN- to C-terminus) of: 1) the signal sequence and V_(K) domain of humananti-HIV gp41 MAb 98.6 (residues 1-107 of the mature protein), 2) a 14amino acid peptide linker(Gly-Ser-Thr-Ser-Gly-Ser-Gly-Lys-Ser-Ser-Glu-Gly-Lys-Gly), 3) the V_(H)domain of MAb 98.6 (residues 1-113 of the mature protein), 4) the hinge,CH2 and CH3 domains of the human IgG2 heavy chain constant region(residues 226 to 477), 5) the 18 residue human IgG3 M1 membrane hinge,6) the CD4 TM domain (residues 372-395), and 7) the ζ CYT domain(residues 31-142). The presence of the IgG2 heavy chain constant domainallows such SAb-Janus kinase and SAb-cytokine receptor subunitconstructs to form disulfide-linked dimers. Derivatives which lack theconstant domain, and thus do not dimerize, are made by oligonucleotidedirected mutagenesis. Other derivatives lacking the Asp codon orcontaining other oligo- or polypeptide linkers at the junction of CD4 TMand the CYT domain of the Janus kinase or cytokine receptor subunit areconstructed by oligonucleotide-directed mutagenesis. In each example,the correct expression plasmid is identified by restriction mapping andits structure confirmed by DNA sequencing.

a) Construction of SAb-mJAK1

pIKSAb-mJAK1 directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe entire mouse JAK1 Janus kinase by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 4.3 kbobtained by digestion of the expression plasmid pIK1.1 with EcoRI andApaI, 2) a fragment of 1.6 kb encoding the SAb EXT domain and part ofthe CD4 TM domain, obtained by digestion of pRT43.2F15γ2 with EcoRI andNgoMI, and 3) a 3.7 kb fragment encoding the remainder of the CD4 TMdomain and the entire mJAK1 protein, obtained by digestion ofpIKCD4-mJAK1 with NgoMI and ApaI.

b) Construction of SAb-mJAK2

pIKSAb-mJAK2 directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe entire mouse JAK2 Janus kinase by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.6 kbencoding the entire mJAK2 protein, obtained by digestion of pIKCD4-mJAK2with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 1.0 kb encoding the remainderof the SAb EXT domain and the CD4 TM domain, obtained by digestion ofpIKSAb-mJAK1 with BamHI and SalI.

c) Construction of SAb-mJAK3

pIKSAb-mJAK3 directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe entire mouse JAK2 Janus kinase by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK3 protein, obtained by digestion of pIKCD4-mJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 1.0 kb encoding the remainderof the SAb EXT domain and the CD4 TM domain, obtained by digestion ofpIKSAb-mJAK1 with BamHI and SalI.

d) Construction of SAb-hTyk2

pIKSAb-hTyk2 directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe entire human Tyk2 Janus kinase by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.5 kbencoding the C-terminus of hTyk2, obtained by digestion of pIKCD4-hTyk2with EcoRI and BspEI, 2) a fragment of 1.6 kb encoding the SAb EXTdomain and a portion of the CD4 TM domain, obtained by digestion ofpRT43.2F15γ2 with EcoRI and NgoMI, and 3) a fragment of 0.4 kb encodingthe remainder of the CD4 TM domain and the N-terminus of the hTyk2protein, obtained by digestion of pIKCD4-hTyk2 with NgoMI and BspEI.

e) Construction of Sab-CD4-hJAK3

pIKSAb-hJAK3 directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe entire human JAK3 Janus kinase by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK3 protein, obtained by digestion of pIKCD4-hJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 1.0 kb encoding the remainderof the SAb EXT domain and the CD4 TM domain, obtained by digestion ofpIKSAb-mJAK1 with BamHI and SalI.

f) Construction of SAb-IL2Rβ

pIKSAb-hIL2R5 directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe human IL2Rβ CYT domain by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 5.0 kbencoding the IL-2R5 CYT domain, obtained by digestion of pIKCD4-hIL2Rβwith SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 1.0 kb encoding the remainderof the SAb EXT domain and the CD4 TM domain, obtained by digestion ofpIKSAb-mJAK1 with BamHI and SalI.

g) Construction of SAb-IL2Rγ

pIKSAb-hIL2Rγ directs the expression of a hybrid protein consisting ofthe SAb EXT and CD4 TM domains of F15γ2 joined at their C-terminus tothe human IL2Rβ CYT domain by an Asp residue. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 4.4 kbencoding the IL-2Rγ CYT domain, obtained by digestion of pIKCD4-hIL2Rβwith SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 1.0 kb encoding the remainderof the SAb EXT domain and the CD4 TM domain, obtained by digestion ofpIKSAb-mJAK1 with BamHI and SalI.

EXAMPLE 3 CPRs comprising a ligand-receptor (CD4) extracellularclustering domain, a ζ family signalling domain and a Janus kinase orcytokine receptor subunit proliferation signaling domain.

This class of chimeric receptors were created by the insertion of a ζfamily CYT signaling domain (e.g. ζ, η, the FcRε γ subunit, B29, and CD3γ, δ and ε subunits) into a CPR between the TM domain and proliferationsignaling (Janus kinase or cytokine receptor subunit) domain. Thesechimeric receptors were constructed from pIK1.1F3SalB, an intermediateplasmid based on pIK1.1F3 (which encodes CD4-ζ). A SalI site wasintroduced into the CD4-ζ coding sequence between the last amino acidand stop codon by oligonucleotide-directed mutagenesis using pIK1.1F3single-stranded DNA with oligonucleotide 23 (SEQ ID NO:23) as a primerand oligonucleotide 24 (SEQ ID N0:24) to identify the correct clone bycolony hybridization. This results in the addition of 2 residues(Val-Asp) at the carboxyl terminus of CD4-ζ. The proliferation signalingdomain of a Janus kinase or cytokine receptor subunit was then joined atthe C-terminus of CD4-ζ using the unique SalI site which adds a Val-Aspdipeptide at the junction. Derivatives lacking the Val-Asp dipeptide orcontaining other oligo- or polypeptide linkers are constructed byoligonucleotide-directed mutagenesis. A similar strategy is used tocreate CPRs containing a ζ family signaling domain at the C-terminus ofthe chimeric protein (e.g., CD4-Janus kinase-ζ and CD4-cytokine receptorsubunit-ζ) by inserting the ζ family CYT domain after the proliferationsignalling CYT domain.

a) Construction of CD4-ζ-mJAK1

pIKCD4-ζ-mJAK1 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the entire mouse JAK1 Janus kinase by a Val -Aspdipeptide. This plasmid was constructed from two DNA fragments: 1) avector fragment of 7.6 kb encoding the entire mJAK1 protein, obtained bydigestion of pIKCD4-mJAK1 with SphI and SalI, 2) a 1.8 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3SalB with SphI and SalI.

b) Construction of CD4-ζ-mJAK2

pIKCD4-ζ-mJAK2 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the entire mouse JAK2 Janus kinase by a Val-Aspdipeptide. This plasmid was constructed from two DNA fragments: 1) avector fragment of 7.6 kb encoding the entire mJAK2 protein, obtained bydigestion of pIKCD4-mJAK2 with SphI and SalI, 2) a 1.8 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3SalB with SphI and SalI.

c) Construction of CD4-ζ-mJAK3

pIKCD4-ζ-mJAK3 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the entire mouse JAK3 Janus kinase by a Val -Aspdipeptide. This plasmid was constructed from two DNA fragments: 1) avector fragment of 7.7 kb encoding the entire mJAK3 protein, obtained bydigestion of pIKCD4-mJAK3 with SphI and SalI, 2) a 1.8 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3SalB with SphI and SalI.

d) Construction of CD4-ζ-hTyk2

pIKCD4-ζ-hTyk2 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the entire human Tyk2 Janus kinase by a Val-Aspdipeptide. This plasmid was constructed from three DNA fragments: 1) avector fragment of 7.5 kb encoding the C-terminus of hTyk2, obtained bydigestion of pIKCD4-hTyk2 with EcoRI and BspEI, 2) a 1.7 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3SalB with EcoRI and SalI, and 3) a 0.3 kb fragmentencoding the N-terminus of hTyk2, obtained by digestion of pIK1.1F3SalBwith SalI and BspEI.

e) Construction of CD4-ζ-hJAK3

pIKCD4-ζ-hJAK3 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the entire human JAK3 Janus kinase by a Val-Aspdipeptide. This plasmid was constructed from two DNA fragments: 1) avector fragment of 7.7 kb encoding the entire hJAK3 protein, obtained bydigestion of pIKCD4-hJAK3 with SphI and SalI, 2) a 1.8 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3Sal B with SphI and SalI.

f) Construction of CD4-ζ-hIL2Rβ

pIKCD4-ζ-hIL2R6 directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the human IL2Rβ CYT domain subunit by a Val-Aspdipeptide. This plasmid is constructed from two DNA fragments: 1) avector fragment of 5.0 kb encoding the hIL2Rβ CYT domain, obtained bydigestion of pIKCD4-hIL2Rβ with SphI and SalI, 2) a 1.8 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3SalB with SphI and SalI.

g) Construction of CD4-ζ-hIL2Rγ

pIKCD4-ζ-hIL2Rγ directs the expression of a hybrid protein consisting ofthe CD4 EXT and TM domains (residues 1 to 395) and ζ CYT domain joinedat their C-terminus to the human IL2Rγ CYT domain by a Val-Aspdipeptide. This plasmid is constructed from two DNA fragments: 1) avector fragment of 4.4 kb encoding the hIL2Rγ CYT domain, obtained bydigestion of pIKCD4-hIL2Rβ with SphI and SalI, 2) a 1.8 kb fragmentencoding the CD4 EXT and TM domains and the ζ CYT domain, obtained bydigestion of pIK1.1F3SalB with SphI and SalI.

EXAMPLE 4 CPRs containing an antibody extracellular clustering domain, aζ family signaling domain and a Janus kinase or cytokine receptorsubunit proliferation signaling domain.

This class of chimeric receptors are created by the insertion of a ζfamily CYT signaling domain (e.g. ζ, η, the FcRε γ subunit, B29, and CD3γ, δ and ε subunits) into an antibody-based CPR between the TM domainand proliferation signaling (Janus kinase or cytokine receptor subunit)domain. These chimeric receptors are constructed from CD4-ζ-Janus kinaseand CD4-ζ-cytokine receptor subunit CPRs, by substituting anantibody-based EXT clustering domain for the CD4 EXT domain. Theproliferation signalling domain of a Janus kinase or cytokine receptorsubunit is joined at the C-terminus of SAb-ζby a Val-Asp dipeptide.Derivatives lacking the Val-Asp dipeptide or containing other oligo- orpolypeptide linkers are constructed by oligonucleotide-directedmutagenesis. A similar strategy is used to create CPRs containing a ζfamily signaling domain at the C-terminus of the chimeric protein (e.g.,SAb-Janus kinase-ζ and SAb-cytokine receptor subunit-ζ) by inserting theζ family CYT domain after the proliferation signalling CYT domain.

a) Construction of SAb-ζ-mJAK1

pIKSAb-ζ-mJAK1 directs the expression of a hybrid protein consisting ofthe 98.6 SAb EXT, CD4 TM and ζ CYT domain joined at their C-terminus tothe entire mouse JAK1 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 4.3 kbobtained by digestion of the expression plasmid pIK1.1 with EcoRI andApaI, 2) a fragment of 1.6 kb encoding the SAb EXT domain and part ofthe CD4 TM domain, obtained by digestion of pRT43.2F15γ2 with EcoRI andNgoMI, and 3) a 4.0 kb fragment encoding the remainder of the CD4 TMdomain, the ζ CYT domain and the entire mJAK1 protein, obtained bydigestion of pIKCD4-ζ-mJAK1 with NgoMI and ApaI.

b) Construction of SAb-ζ-mJAK2

pIKSAb-ζ-mJAK2 directs the expression of a hybrid protein consisting ofthe 98.6 SAb EXT, CD4 TM and ζ CYT domain joined at their C-terminus tothe entire mouse JAK2 Janus kinase by a Val -Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 7.6 kbencoding the entire mJAK2 protein, obtained by digestion of pIKCD4-mJAK2with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 1.4 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the ζ CYT domain, obtainedby digestion of pIKSAb-ζ-mJAK1 with BamHI and SalI.

c) Construction of SAb-ζ-mJAK3

pIKSAb-ζ-mJAK3 directs the expression of a hybrid protein consisting ofthe 98.6 SAb EXT, CD4 TM and ζ CYT domain joined at their C-terminus tothe entire mouse JAK3 Janus kinase by a Val -Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK3 protein, obtained by digestion of pIKCD4-mJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 1.4 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the ζ CYT domain, obtainedby digestion of pIKSAb-ζ-mJAK1 with BamHI and SalI.

d) Construction of SAb-ζ-hTyk2

pIKSAb-ζ-hTyk2 directs the expression of a hybrid protein consisting ofthe 98.6 EXT, CD4 TM and ζ CYT domain joined at their C-terminus to theentire human Tyk2 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.5 kbencoding the C-terminus of hTyk2, obtained by digestion of pIKCD4-hTyk2with EcoRI and BspEI, 2) a fragment of 1.6 kb encoding the SAb EXTdomain and a portion of the CD4 TM domain, obtained by digestion ofpIKSAb-ζ-mJAK1 with EcoRI and NgoMI, and 3) a fragment of 1.6 kbencoding the remainder of the CD4 TM domain, the ζ CYT domain and theN-terminus of the hTyk2 protein, obtained by digestion of pIKCD4-ζ-hTyk2with NgoMI and BspEI.

e) Construction of SAb-ζ-hJAK3

pIKCD4-ζ-hJAK3 directs the expression of a hybrid protein consisting ofthe 98.6 EXT, CD4 TM and ζ CYT domain joined at their C-terminus to theentire human JAK3 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire hJAK3 protein, obtained by digestion of pIKCD4-hJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 1.4 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the ζ CYT domain, obtainedby digestion of pIKSAb-ζ-mJAK1 with BamHI and SalI.

f) Construction of SAb-ζ-hIL2Rβ

pIKSAb-ζ-hIL2Rβ directs the expression of a hybrid protein consisting ofthe 98.6 EXT, CD4 TM and ζ CYT domain joined at their C-terminus to thehuman IL2Rβ CYT domain by a Val -Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 5.0 kbencoding the hIL2RβCYT domain, obtained by digestion of pIKCD4-hIL2Rβwith SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 1.4 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the ζ CYT domain, obtainedby digestion of pIKSAb-ζ-mJAK1 with BamHI and SalI.

g) Construction of SAb-ζ-hIL2Rγ

pIKSAb-ζ-hIL2Rγ directs the expression of a hybrid protein consisting ofthe 98.6 EXT, CD4 TM and ζ CYT domain joined at their C-terminus to thehuman IL2Rβ CYT domain by a Vat-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 4.4 kbencoding the hIL2RγCYT domain, obtained by digestion of pIKCD4-hIL2Rγwith SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 1.4 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the ζ CYT domain, obtainedby digestion of pIKSAb-ζ-mJAK1 with BamHI and SalI.

EXAMPLE 5 CPRs containing a ligand-receptor (CD4) extracellularclustering domain, a Syk family kinase signaling domain and a Januskinase or a cytokine receptor subunit proliferation signaling domain.

This class of chimeric receptors are created by the insertion of a Sykfamily kinase (e.g., Syk and ZAP-70) into a CPR between the TM domainand proliferation signaling (Janus kinase or cytokine receptor subunit)domain. These chimeric receptors are constructed from CD4-ζ-Janus kinaseor CD4-ζ-cytokine receptor subunit CPRs, by replacing the ζ family CYTdomain with the entire Syk family polypeptide. CPRs based on the Sykkinase are made from the intermediate plasmid pIK1.1CD4-Syk whichdirects the expression of a hybrid protein consisting of the CD4 EXT andTM domains joined to the entire human Syk polypeptide by a Glu residue.This plasmid is constructed from two fragments: 1) a vector fragment of5.7 kb encoding the CD4 EXT and TM domains, obtained by digestion ofpIK1.1F3Sal with ApaI, extension of the cohesive end to a blunt end withT4 DNA polymerase and dNTPs, followed by digestion with SalI, and 2) a1.8 kb PCR fragment encoding human Syk kinase, generated using ΨHM3-Syk(provided by Edward Clark, U. of Washington, Seattle, Wash.) as a PCRtemplate with oligonucleotides 25 & 26 (SEQ ID N0:25 & 26) as primers tointroduce XhoI and EcoRV sites at the 5' and 3' ends, respectively,followed by digestion with XhoI and EcoRV. The Janus kinase or cytokinereceptor subunit is then joined at the C-terminus of CD4-Syk using theunique SalI site which adds a Val -Asp dipeptide at the junction.Derivatives lacking the Val -Asp dipeptide or containing other oligo- orpolypeptide linkers are constructed by oligonucleotide-directedmutagenesis. A similar strategy is used to create CPRs containing a Sykfamily kinase at the C-terminus of the chimeric protein (e.g., CD4-Januskinase-ζ and CD4-cytokine receptor subunit-ζ) by inserting the Sykfamily kinase after the proliferation signalling CYT domain.

a) Construction of CD4-Syk-mJAK1

pIKCD4-Syk-mJAK1 directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues 1 to 395) and the entire Sykprotein joined at their C-terminus to the entire mouse JAK1 Janus kinaseby a Val-Asp dipeptide. This plasmid is constructed from two DNAfragments: 1) a vector fragment of 7.7 kb encoding the entire mJAK1protein, obtained by digestion of pIKCD4-mJAK1 with SphI and SalI, and2) a 3.3 kb fragment encoding the CD4 EXT and TM domains and the entireSyk protein, obtained by digestion of pIK1.1CD4-Syk with SphI and SalI.

b) Construction of CD4-Syk-mJAK2

pIKCD4-Syk-mJAK2 directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues 1 to 395) and the entire Sykprotein joined at their C-terminus to the entire mouse JAK2 Janus kinaseby a Val-Asp dipeptide. This plasmid is constructed from two DNAfragments: 1) a vector fragment of 7.6 kb encoding the entire mJAK2protein, obtained by digestion of pIKCD4-mJAK2 with SphI and SalI, and2) a 3.3 kb fragment encoding the CD4 EXT and TM domains and the entireSyk protein, obtained by digestion of pIK1.1CD4-Syk with SphI and SalI.

c) Construction of CD4-Syk-mJAK3

pIKCD4-Syk-mJAK3 directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues 1 to 395) and the entire Sykprotein joined at their C-terminus to the entire mouse JAK3 Janus kinaseby a Val-Asp dipeptide. This plasmid is constructed from two DNAfragments: 1) a vector fragment of 7.7 kb encoding the entire mJAK3protein, obtained by digestion of pIKCD4-mJAK3 with SphI and SalI, and2) a 3.3 kb fragment encoding the CD4 EXT and TM domains and the entireSyk protein, obtained by digestion of pIK1.1CD4-Syk with SphI and SalI.

d) Construction of CD4-Syk-hTyk2

pIKCD4-Syk-hTyk2 directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues 1 to 395) and the entire Sykprotein joined at their C-terminus to the entire human Tyk2 Janus kinaseby a Val-Asp dipeptide. This plasmid is constructed from three DNAfragments: 1) a vector fragment of 7.5 kb encoding the C-terminus ofhTyk2, obtained by digestion of pIKCD4-hTyk2 with EcoRI and BspEI, 2) a3.3 kb fragment encoding the CD4 EXT and TM domains and the entire Sykprotein, obtained by digestion of pIK1.1CD4-Syk with EcoRI and SalI, and3) an 0.3 kb fragment encoding the N-terminus of hTyk2, obtained bydigestion of pIK1.1F3SalB with SalI and BspEI.

e) Construction of CD4-Syk-hJAK3

pIKCD4-Syk-hJAK3 directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues 1 to 395) and the entire Sykprotein joined at their C-terminus to the entire human JAK3 Janus kinaseby a Val-Asp dipeptide. This plasmid is constructed from two DNAfragments: 1) a vector fragment of 7.7 kb encoding the entire hJAK3protein, obtained by digestion of pIKCD4-hJAK3 with SphI and SalI, and2) a 3.3 kb fragment encoding the CD4 EXT and TM domains and the entireSyk protein, obtained by digestion of pIK1.1CD4-Syk with SphI and SalI.

f ) Construction of CD4-Syk-hIL2Rβ

pIKCD4-Syk-hIL2Rβ directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues 1 to 395) and the entire Sykprotein joined at their C-terminus to the human IL2Rβ CYT domain by aVat-Asp dipeptide. This plasmid is constructed from two DNAfragments: 1) a vector fragment of 5.0 kb encoding the hIL2Rβ CYTdomain, obtained by digestion of pIKCD4-hIL2Rβ with SphI and SalI, 2) a3.3 kb fragment encoding the CD4 EXT and TM domains and the entire Sykprotein, obtained by digestion of pIK1.1CD4-Syk with SphI and SalI.

g) Construction of CD4-Syk-hIL2Rγ

pIKCD4-Syk-hIL2Rγ directs the expression of a hybrid protein consistingof the CD4 EXT and TM domains (residues to 395) and the entire Sykprotein joined at their C-terminus to the human IL2Rγ CYT domain by aVal-Asp dipeptide. This plasmid is constructed from two DNAfragments: 1) a vector fragment of 4.4 kb encoding the hIL2Rβ CYTdomain, obtained by digestion of pIKCD4-hIL2Rβ with SphI and SalI, 2) a3.3 kb fragment encoding the CD4 EXT and TM domains and the entire Sykprotein, obtained by digestion of pIK1.1CD4-Syk with SphI and SalI.

EXAMPLE 6 CPRs containing an antibody extracellular clustering domain,and a Syk family kinase signaling domain and Janus kinase & cytokinereceptor subunit proliferation signaling domain

This class of chimeric receptors are created by the insertion of a Sykfamily kinase (e.g. Syk and ZAP-70) into an antibody-based CPR betweenthe TM domain and proliferation signaling (Janus kinase or cytokinereceptor subunit) domain. These chimeric receptors are constructed fromCD4-Syk-Janus kinase and CD4-Syk-cytokine receptor subunit CPRs, bysubstituting an antibody-based EXT clustering domain for the CD4 EXTdomain. The proliferation signaling domain of a Janus kinase or cytokinereceptor subunit is joined at the C-terminus of SAb-Syk by a Val-Aspdipeptide. Derivatives lacking the Val-Asp dipeptide or containing otheroligo- or polypeptide linkers are constructed byoligonucleotide-directed mutagenesis. A similar strategy is used tocreate CPRs containing a Syk family kinase at the C-terminus of thechimeric protein (e.g., SAb-Janus kinase-Syk kinase and SAb-cytokinereceptor subunit-Syk kinase) by inserting the Syk family kinase afterthe proliferation signalling CYT domain.

a) Construction of SAb-Syk-mJAK1

pIKSAb-Syk-mJAK1 directs the expression of a hybrid protein consistingof the 98.6 SAb EXT, CD4 TM and the entire Syk protein joined at theirC-terminus to the entire mouse JAK1 Janus kinase by a Val-Asp dipeptide.This plasmid is constructed from three DNA fragments: 1) a vectorfragment of 7.7 kb encoding the entire mJAK1 protein, obtained bydigestion of pIKCD4-mJAK1 with SphI and SalI, 2) a fragment of 1.7 kbencoding the SAb EXT domain and part of the CD4 TM domain, obtained bydigestion of pIKSAb-mJAK1 with SphI and NgoMI, and 3) a 2.0 kb fragmentencoding the remainder of the CD4 TM domain and the entire Syk protein,obtained by digestion of pIKCD4-Syk-mJAK1 with NgoMI and SalI.

b) Construction of SAb-Syk-mJAK2

pIKSAb-Syk-mJAK2 directs the expression of a hybrid protein consistingof the 98.6 SAb EXT, CD4 TM and Syk CYT domain joined at theirC-terminus to the entire mouse JAK2 Janus kinase by a Val-Asp dipeptide.This plasmid is constructed from three DNA fragments: 1) a vectorfragment of 7.6 kb encoding the entire mJAK2 protein, obtained bydigestion of pIKCD4-mJAK2 with SphI and SalI, 2) a fragment of 0.7 kbencoding the N-terminal portion of the SAb EXT domain, obtained bydigestion of pIKSAb-ζ-mJAK1 with SphI and BamHI, and 3) a fragment of3.0 kb encoding the remainder of the SAb EXT domain, the CD4 TM domainand the entire Syk protein, obtained by digestion of pIKSAb-Syk-mJAK1with BamHI and SalI.

c) Construction of SAb-Syk-mJAK3

pIKSAb-Syk-mJAK3 directs the expression of a hybrid protein consistingof the 98.6 SAb EXT, CD4 TM and Syk CYT domain joined at theirC-terminus to the entire mouse JAK3 Janus kinase by a Val-Asp dipeptide.This plasmid is constructed from three DNA fragments: 1) a vectorfragment of 7.7 kb encoding the entire mJAK3 protein, obtained bydigestion of pIKCD4-mJAK3 with SphI and SalI, 2) a fragment of 0.7 kbencoding the N-terminal portion of the SAb EXT domain, obtained bydigestion of pIKSAb-ζ-mJAK1 with SphI and BamHI, and 3) a fragment of3.0 kb encoding the remainder of the SAb EXT domain, the CD4 TM domainand the entire Syk protein, obtained by digestion of pIKSAb-Syk-mJAK1with BamHI and SalI.

d) Construction of SAb-Syk-hTyk2

pIKSAb-Syk-hTyk2 directs the expression of a hybrid protein consistingof the 98.6 EXT, CD4 TM and Syk CYT domain joined at their C-terminus tothe entire human Tyk2 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 7.5 kbencoding the C-terminus of hTyk2, obtained by digestion of pIKCD4-hTyk2with EcoRI and BspEI, 2) a 1.6 kb fragment encoding the SAb EXT and partof the CD4 TM domain, obtained by digestion of pIKSAb-mJAK1 with EcoRIand NgoMI, and 3) an 2.3 kb fragment encoding the remainder of the CD4TM domain, the entire human Syk protein and the N-terminus of hTyk2,obtained by digestion of pIKCD4-Syk-hTyk2 with NgoMI and BspEI.

e) Construction of SAb-Syk-hJAK3

pIKCD4-Syk-hJAK3 directs the expression of a hybrid protein consistingof the 98.6 EXT, CD4 TM and Syk CYT domain joined at their C-terminus tothe entire human JAK3 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire hJAK3 protein, obtained by digestion of pIKCD4-hJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 3.0 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the entire Syk protein,obtained by digestion of pIKSAb-Syk-mJAK1 with BamHI and SalI.

f) Construction of SAb-Syk-hIL2Rβ

pIKSAb-Syk-hIL2Rβ directs the expression of a hybrid protein consistingof the 98.6 EXT, CD4 TM and Syk CYT domain joined at their C-terminus tothe human IL2Rβ CYT domain by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 5.0 kbencoding the hIL2Rβ CYT domain, obtained by digestion of pIKCD4-hIL2Rβwith SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 3.0 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the entire Syk protein,obtained by digestion of pIKSAb-Syk-mJAK1 with BamHI and SalI.

g) Construction of SAb-Syk-hIL2Rγ

pIKSAb-Syk-hIL2Rγ directs the expression of a hybrid protein consistingof the 98.6 EXT, CD4 TM and Syk CYT domain joined at their C-terminus tothe human IL2Rγ CYT domain by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 4.4 kbencoding the hIL2Rγ CYT domain, obtained by digestion of pIKCD4-hIL2Rγwith SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-ζ-mJAK1with SphI and BamHI, and 3) a fragment of 3.0 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the entire Syk protein,obtained by digestion of pIKSAb-Syk-mJAK1 with BamHI and SalI.

EXAMPLE 7 CPRs containing an intracellular clustering domain: and aJanus kinase or cytokine receptor subunit proliforation signaling domain

Expression vectors for FKBP-Janus kinase and FKBP-cytokine receptorsubunit hybrids are created by replacing the CD4 EXT and TM domains inCD4-Janus kinase and CD4-cytokine receptor subunit hybrids with an(FKBP)₃ cassette consisting of three repeats of an FKBP module, each ofwhich contains residues 2-108 of FKBP12, the human FK506 binding protein(Standaert et al. (1990) Nature 346:671-674). The first FKBP module ispreceded by an initiator Met codon, then a two amino linker, Val-Glu.This same Val-Glu dipeptide is found between module 1 & 2 and betweenmodules 2 & 3. The last module is followed by a Val-Asp dipeptide whichlinks it to the first codon of the proliferation signalling domain.Other derivatives lacking the Val -Asp dipeptide or containing otheroligo- or polypeptide linkers at the junction of the (FKBP)₃ cassetteand the Janus kinase or cytokine receptor subunit CYT domain areconstructed by oligonucleotide-directed mutagenesis. Still otherderivatives of (FKBP)₃ lacking the Val-Glu dipeptide linkers orcontaining other oligo- or polypeptide linkers are constructed byoligonucleotide-directed mutagenesis. The (FKBP)₃ cassette isconstructed in two steps. First, a plasmid containing the FKBP module,pFKBP, is constructed from two DNA fragment: 1) a vector fragment of 2.9kb, obtained by digestion of pBluescriptSK (Strategene, La Jolla,Calif.) with XhoI and SalI, and treatment with calf intestine alkalinephosphatase, and 2) a DNA fragment of 0.3 kb encoding the FKBP module,obtained by PCR and digested with XhoI and SalI. The PCR product isprepared using as a template oligo dT-primed first-strand cDNA made fromactivated T cell mRNA (as described in Example 1) and oligos nucleotides27 and 28 (SEQ ID NOS: 27 & 28) as the PCR primers. DNA sequenceanalysis is employed to confirm the correct structure of the module.Secondly, plasmid pBSK(FKBP)₃ containing the (FKBP)₃ cassette isconstructed from three fragments: 1) a vector fragment of 2.9 kb,obtained by digestion of pBluescriptSK with EcoRI and SalI, 2) a DNAfragment of 1.0 kb encoding (FKBP)₃, obtained by extensive self-ligationand subsequent digestion with XhoI and SalI of an 0.3 kb fragmentencoding the FKBP module, obtained by digestion of pFKBP with XhoI andSalI, and 3) an EcoRI-XhoI adapter composed of oligos nucleotides 29 and30 (SEQ ID NOS. 29 & 30).

a) Construction of FKBP-mJAK1

pIKFKBP-mJAK1 directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe entire mouse JAK1 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 4.3 kb,obtained by digestion of the expression plasmid pIK1.1 with EcoRI andApaI, 2) a fragment of 1.0 kb encoding the (FKBP)₃ cassette, obtained bydigestion of pBSK(FKBP)₃ with EcoRI and SalI, and 3) a 3.6 kb fragmentencoding the entire mJAK1 protein, obtained by digestion of pIKCD4-mJAK1with SalI and ApaI.

b) Construction of FKBP-mJAK2

pIKFKBP-mJAK2 directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe entire mouse JAK2 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from two DNA fragments: 1) a vector fragment of 7.6 kbencoding the entire mJAK2 protein, obtained by digestion of pIKCD4-mJAK2with SphI and SalI, and 2) a fragment of 1.1 kb encoding the (FKBP)₃cassette, obtained by digestion of pIKFKBP-mJAK1 with SphI and SalI.

c) Construction of FKBP-mJAK3

pIKFKBP-mJAK3 directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe entire mouse JAK3 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from two DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK3 protein, obtained by digestion of pIKCD4-mJAK3with SphI and SalI, and 2) a fragment of 1.1 kb encoding the (FKBP)₃cassette, obtained by digestion of pIKFKBP-mJAK1 with SphI and SalI.

d) Construction of FKBP-hTyk2

pIKFKBP-hTyk2 directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe entire human Tyk2 Janus kinase by a Val -Asp dipeptide. This plasmidis constructed from three DNA fragments: 1) a vector fragment of 7.5 kbencoding the C-terminus of hTyk2, obtained by digestion of pIKCD4-hTyk2with EcoRI and BspEI, 2) a fragment of 1.0 kb encoding the (FKBP)₃cassette, obtained by digestion of pIKFKBP-mJAK1 with EcoRI and SalI,and 3) a fragment of 0.3 kb encoding the N-terminus of the hTyk2protein, obtained by digestion of pIKCD4-hTyk2 with SalI and BspEI.

e) Construction of FKBP-hJAK3

pIKFKBP-hJAK3 directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe entire human JAK3 Janus kinase by a Val-Asp dipeptide. This plasmidis constructed from two DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire hJAK3 protein, obtained by digestion of pIKCD4-hJAK3with SphI and SalI, and 2) a fragment of 1.1 kb encoding the (FKBP)₃cassette, obtained by digestion of pIKFKBP-mJAK1 with SphI and SalI.

f) Construction of FKBP-IL2Rβ

pIKFKBP-hIL2Rβ directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe human IL2Rβ CYT domain by a Val-Asp dipeptide. This plasmid isconstructed from two DNA fragments: 1) a vector fragment of 5.0 kbencoding the hIL2Rβ CYT domain, obtained by digestion of pIKCD4-hIL2Rγwith SphI and SalI, and 2) a fragment of 1.1 kb encoding the (FKBP)₃cassette, obtained by digestion of pIKFKBP-mJAK1 with SphI and SalI.

g) Construction of FKBP-IL2Rγ

pIKFKBP-hIL2Rγ directs the expression of a hybrid protein consisting ofthe (FKBP)₃ coding sequence of pBSK(FKBP)₃ joined at its C-terminus tothe human IL2Rγ CYT domain by a Val -Asp dipeptide. This plasmid isconstructed from two DNA fragments: 1) a vector fragment of 4.4 kbencoding the hIL2Rγ CYT domain, obtained by digestion of pIKCD4-hIL2Rγwith SphI and SalI, and 2) a fragment of 1.1 kb encoding the (FKBP)₃cassette, obtained by digestion of pIKFKBP-mJAK1 with SphI and SalI.

EXAMPLE 8 CPRs containing a ligand-receptor (CD4) extracellularclustering domain; an intracellular clustering domain; and a Januskinase or cytokine receptor subunit proliferation signaling domain

This class of chimeric receptors are created by the insertion of an(FKBP)₃ cassette into a CD4-Janus kinase or CD4-cytokine receptorsubunit CPR between the TM domain and proliferation signaling domain.These chimeric receptors are constructed from pIKCD4-(FKBP)₃, anintermediate plasmid based on pIK1.1F3Sal. The proliferation signalingdomain of a Janus kinase or cytokine receptor subunit is then joined atthe C-terminus of CD4-(FKBP)₃ using the unique SalI site which adds aVal -Asp dipeptide at the junction. Derivatives lacking the Val -Aspdipeptide or containing other oligo- or polypeptide linkers areconstructed by oligonucleotide-directed mutagenesis. A similar strategyis used to create CPRs containing an (FKBP)₃ cassette at the C-terminusof the chimeric protein (e.g., CD4-Janus kinase-FKBP and CD4-cytokinereceptor subunit-FKBP) by inserting the (FKBP)₃ cassette after theproliferation signalling CYT domain. pIKCD4-(FKBP)₃ is constructed fromtwo DNA fragments: 1) a vector fragment of 5.8 kb encoding the CD4 EXTand TM domains, obtained by digestion of pIK1.1F3Sal with SalI followedby treatment with calf intestine alkaline phosphatase, and 2) a 1.0 kbfragment encoding the (FKBP)₃ cassette, obtained by digestion ofpBSK(FKBP)₃ with XhoI and SalI. Clones with the (FKBP)₃ cassette in thecorrect in-frame orientation are confirmed by restriction mapping.

a) Construction of CD4-FKBP-mJAK1

pIKCD4-FKBP-mJAK1 directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to theentire mouse JAK1 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from two DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK1, obtained by digestion of pIKCD4-mJAK1 withSphI and SalI, and 2) a fragment of 2.3 kb encoding CD4-(FKBP)₃,obtained by digestion of pIKCD4-(FKBP)5 with SphI and SalI.

b) Construction of CD4-FKBP-mJAK2

pIKCD4-FKBP-mJAK2 directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to theentire mouse JAK2 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from two DNA fragments: 1) a vector fragment of 7.6 kbencoding the entire mJAK2, obtained by digestion of pIKCD4-mJAK2 withSphI and SalI, and 2) a fragment of 2.3 kb encoding CD4-(FKBP)₃,obtained by digestion of pIKCD4-(FKBP)₃ with SphI and SalI.

c) Construction of CD4-FKBP-mJAK3

pIKCD4-FKBP-mJAK3 directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to theentire mouse JAK3 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from two DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK3, obtained by digestion of pIKCD4-mJAK3 withSphI and SalI, and 2) a fragment of 2.3 kb encoding CD4-(FKBP)₃,obtained by digestion of pIKCD4-(FKBP)₃ with SphI and SalI.

d) Construction of CD4-FKBP-hTyk2

pIKCD4-FKBP-hTyk2 directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to theentire human Tyk2 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.5 kbencoding the C-terminus of hTyk2, obtained by digestion of pIKCD4-hTyk2with EcoRI and BspEI, 2) a fragment of 2.3 kb encoding the CD4-(FKBP)₃cassette, obtained by digestion of pIKCD4-(FKBP)₃ with EcoRI and SalI,and 3) a fragment of 0.3 kb encoding the N-terminus of the hTyk2protein, obtained by digestion of pIKCD4-hTyk2 with SalI and BspEI.

e) Construction of CD4-FKBP-hJAK3

pIKCD4-FKBP-hJAK3 directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to theentire human JAK3 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from two DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire hJAK3, obtained by digestion of pIKCD4-hJAK3 withSphI and SalI, and 2) a fragment of 2.3 kb encoding CD4-(FKBP)₃,obtained by digestion of pIKCD4-(FKBP)₃ with SphI and SalI.

f) Construction of CD4-FKBP-IL2Rβ

pIKCD4-FKBP-hIL2Rβ directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to thehIL2Rβ CYT domain by a Val-Asp dipeptide. This plasmid is constructedfrom two DNA fragments: 1) a vector fragment of 5.0 kb encoding thehIL2Rβ CYT domain, obtained by digestion of pIKCD4-hIL2Rβ with SphI andSalI, and 2) a fragment of 2.3 kb encoding CD4-(FKBP)₃, obtained bydigestion of pIKCD4-(FKBP)₃ with SphI and SalI.

g) Construction of CD4-FKBP-IL2Rγ

pIKCD4-FKBP-hIL2Rγ directs the expression of a hybrid protein consistingof the CD4-(FKBP)₃ coding sequence joined at its C-terminus to thehIL2Rβ CYT domain by a Val-Asp dipeptide. This plasmid is constructedfrom two DNA fragments: 1) a vector fragment of 4.4 kb encoding theentire mJAK1, obtained by digestion of pIKCD4-hIL2Rγ with SphI and SalI,and 2) a fragment of 2.3 kb encoding CD4-(FKBP)₃, obtained by digestionof pIKCD4-(FKBP)₃ with SphI and SalI.

EXAMPLE 9 CPRs containing antibody extracellular clustering domain, anintracellular clustering domain: and a Janus kinase or cytokine receptorsubunit proliferation domain

This class of chimeric receptors are created by the insertion of an(FKBP)₃ cassette into a SAb-Janus kinase or SAb-cytokine receptorsubunit CPR between the TM domain and proliferation signalling domain.The proliferation signalling domain of a Janus kinase or cytokinereceptor subunit is joined at the C-terminus of SAb-(FKBP)₃ using theSalI site which adds a Val-Asp dipeptide at the junction. Derivativeslacking the Val -Asp dipeptide or containing other oligo- or polypeptidelinkers are constructed by oligonucleotide-directed mutagenesis. Asimilar strategy is used to create CPRs containing an (FKBP)₃ cassetteat the C-terminus of the chimeric protein (e.g., SAb-Janus kinase-FKBPand SAb-cytokine receptor subunit-FKBP) by inserting the (FKBP)₃cassette after the proliferation signalling CYT domain.

a) Construction of SAb-FKBP-mJAK1

pIKSAb-FKBP-mJAK1 directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to theentire mouse JAK1 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK1 protein, obtained by digestion of pIKCD4-mJAK1with SphI and SalI, 2) a fragment of 17 kb encoding the SAb EXT domainand a portion of the CD4 TM domain, obtained by digestion ofpIKSAb-mJAK1 with SphI and NgoMI, and 3) a 1.0 kb fragment encoding theremainder of the CD4 TM domain and the (FKBP)₃ cassette, obtained bydigestion of pIKCD4-(FKBP)₃ with NgoMI and SalI.

b) Construction of SAb-FKBP-mJAK2

pIKSAb-FKBP-mJAK2 directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to theentire mouse JAK2 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.6 kbencoding the entire mJAK2 protein, obtained by digestion of pIKCD4-mJAK2with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 2.0 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the (FKBP)₃ cassette,obtained by digestion of pIKSAb-FKBP-mJAK1 with BamHI and SalI.

c) Construction of SAb-FKBP-mJAK3

pIKSAb-FKBP-mJAK3 directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to theentire mouse JAK3 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK3 protein, obtained by digestion of pIKCD4-mJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 2.0 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the (FKBP)₃ cassette,obtained by digestion of pIKSAb-FKBP-mJAK1 with BamHI and SalI.

d) Construction of SAb-FKBP-hTyk2

pIKSAb-FKBP-hTyk2 directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to theentire human Tyk2 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.5 kbencoding the C-terminus of the Tyk2 protein, obtained by digestion ofpIKCD4-hTyk2 with EcoRI and BspEI, 2) a fragment of 1.6 kb encoding theSAb EXT domain and a portion of the CD4 TM domain, obtained by digestionof pIKSAb-mJAK1 with EcoRI and NgoMI, and 3) a fragment of 1.5 kbencoding the remainder of the CD4 TM domain, the (FKBP)₃ cassette andthe N-terminus of hTyk2, obtained by digestion of pIKCD4-FKBP-hTyk2 withNgoMI and BspEI.

e) Construction of SAb-FKBP-hJAK3

pIKSAb-FKBP-hJAK3 directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to theentire human JAK3 Janus kinase by a Val-Asp dipeptide. This plasmid isconstructed from three DNA fragments: 1) a vector fragment of 7.7 kbencoding the entire mJAK2 protein, obtained by digestion of pIKCD4-hJAK3with SphI and SalI, 2) a fragment of 0.7 kb encoding the N-terminalportion of the SAb EXT domain, obtained by digestion of pIKSAb-mJAK1with SphI and BamHI, and 3) a fragment of 2.0 kb encoding the remainderof the SAb EXT domain, the CD4 TM domain and the (FKBP)₃ cassette,obtained by digestion of pIKSAb-FKBP-mJAK1 with BamHI and SalI.

f) Construction of SAb-FKBP-IL2Rβ

pIKSAb-FKBP-hIL2R5 directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to thehIL2Rβ CYT domain by a Val -Asp dipeptide. This plasmid is constructedfrom three DNA fragments: 1) a vector fragment of 5.0 kb encoding thehIL2Rβ CYT domain, obtained by digestion of pIKCD4-hIL2Rβ with SphI andSalI, 2) a fragment of 0.7 kb encoding the N-terminal portion of the SAbEXT domain, obtained by digestion of pIKSAb-mJAK1 with SphI and BamHI,and 3) a fragment of 2.0 kb encoding the remainder of the SAb EXTdomain, the CD4 TM domain and the (FKBP)₃ cassette, obtained bydigestion of pIKSAb-FKBP-mJAK1 with BamHI and SalI.

g) Construction of SAb-FKBP-IL2Rγ

pIKSAb-FKBP-hIL2Rγ directs the expression of a hybrid protein consistingof the SAb EXT domain, CD4 TM domain and (FKBP)₃ cassette joined to thehIL2Rγ CYT domain by a Val-Asp dipeptide. This plasmid is constructedfrom three DNA fragments: 1) a vector fragment of 4.4 kb encoding thehIL2Rγ CYT domain, obtained by digestion of pIKCD4-hIL2Rγ with SphI andSalI, 2) a fragment of 0.7 kb encoding the N-terminal portion of the SAbEXT domain, obtained by digestion of pIKSAb-mJAK1 with SphI and BamHI,and 3) a fragment of 2.0 kb encoding the remainder of the SAb EXTdomain, the CD4 TM domain and the (FKBP)₃ cassette, obtained bydigestion of pIKSAb-FKBP-mJAK1 with BamHI and SalI.

EXAMPLE 10 Expression of CPRs

To determine whether CPR polypeptides can be expressed and properlyfolded, each construct was initially transfected into a model mammaliancell, the human 293 embryonic kidney cell line (ATCC CRL1573). Followingtransfection, the expression of each construct was evaluated byradioimmunoprecipitation, and its transport to the cell surface (forCPRs comprising a ligand-receptor or antibody EXT domain) was evaluatedby fluorescent-activated cell sorting (FACS) analysis.

a) Transfection of human 293 cells with CPR expression vectors

CPRs were constructed in pIK mammalian expression plasmids as describedand transfected into human 293 cells. 293 cells were grown in completeDMEM (JRH Biosciences, Lenexa, Kans.), 1 g/1 glucose, 10% donor calfserum (JRH Biosciences) and passaged at 1:10 split ratio every 3 days.Twenty-four hours prior to transfection, 293 cells were plated at 5×10⁵cells per 10 cm plate. Ten micrograms of plasmid DNA was transfectedonto a 10 cm dish of 293 cells by the calcium phosphate coprecipitationmethod (Wigler et al. (1979) Cell 16:777). Twenty-four hours aftertransfection, the cells were fed with fresh complete DMEM media. Theexpression of CPRs was evaluated by FACS analysis andradioimmunoprecipitation at 48 hours post-transfection.

b) FACS analysis of CPR expression in 293 cells

Transfected 293 cells were rinsed once with PBS and incubated in 150 mMNaCl, 40 mM Tris-HCl pH7.5, 1 mM EDTA solution for 5 minutes at roomtemperature. Cells were collected from plates, centrifuged andresuspended in PBS/1% FCS. Approximately 1×10⁶ cells/sample were staineddirectly with saturating concentrations of a fluorescein(FITC)-conjugated anti-CD4 monoclonal antibody (MAb) (Becton DickinsonImmunocytometry Systems, San Jose, Calif.). Mouse FITC-IgG1 and PE-IgG2awere used as negative control MAbs. 293 cells transfected with 10 μg ofPIKF3, which expresses CD4-ζ, were used as a positive control. All FACSanalyses were performed in a FACScan (Becton Dickinson) as previouslydescribed (Weiss and Stobo, (1984) J. Exp. Med., 160:1284-1299). FACSanalysis of cells transfected with CPRs containing a CD4 EXT clusteringdomain demonstrated that up to 50% of cells were stained positive withthe anti-CD4 MAb (FIG. 3). 293 cells transfected with CPR constructscontaining a SAb EXT clustering domain are evaluated for expression ofthe CPR by staining with a fluorescein-conjugated mouse anti-human IgMAb, using isotype-matched mouse FITC-IgG as a negative control. 293cells transfected with CPR constructs containing an intracellularclustering domain (e.g., FKBP, glucocorticoid receptor) are evaluatedfor expression of the CPR by first partially permeabilizing the cellswith 70% methanol for 30 seconds on ice, followed by staining the cellswith FITC-conjugated anti-PSD antibody (see Example 10C). An isotypematched mouse FITC-IgG is used as a negative control.

c) Radioimmunoprecipitation of CPRs expressed in 293 cells

Transfected 293 cells were rinsed once with RPMI medium lackingmethionine. Cells were cultured for additiona 18 hours in 2 μl ofmethionine-deficient RPMI supplemented with 200 μCi ³⁵ S!-methionine(1160 C/mmol, ICN Biomedicals, Inc., Irvine, Calif.). The labelled cellswere lysed in RIPA buffer (50 mM Tris, 150 mM NaCl, 1% Triton-X 100,0.5% deoxycholate, 0.1% sodium dodecyl sulfate (SDS)). Forimmunoprecipitation, cell lysates were precleared with 10 μl Pansorbin(Calbiochem, La Jolla, Calif.) and incubated with either OKT4A(anti-CD4) (Ortho Diagnostic Systems, Raritan, N.J.), polyclonalanti-mouse/human JAK1 (UBI, Lake Placid, N.Y.), polyclonal anti-mouseJAK2 (UBI), or polyclonal anti-mouse JAK3 (UBI), at 4° C. for 1 hour.Ten microliters of Pansorbin was then added to the lysates toprecipitate the antibody-bound antigen. Immunoprecipitates were washedthree times in RIPA buffer, boiled in SDS sample buffer (50 mM Tris-HCl,pH 6.8, 100 mM DTT, 2% SDS, 0.1% bromophenol blue, 10% glycerol ) andanalyzed by 8% SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Gelswere fixed in 20% methanol/10% acetic acid and soaked in Enlighteningsolution (NEN Research Products, Boston, Mass.) for 15 min, dried andsubjected to autoradiography. SDS-PAGE analysis revealed the expressionof CPRs in 293 cells of the expected molecular mass (FIG. 4)

EXAMPLE 11 Biochemical and Biological Properties of CPRs Expressed inHuman CD8⁺ T cells

a) Construction of CPR-Expressing Retroviral Vectors

Sequences encoding the CPRs CD4-mJAK1, CD4-ζ-mJAK1, CD4-mJAK3,CD4-ζ-mJAK3, CD4-hTyk2, and CD4-ζ-hTyk2 were inserted between the EcoRIand ApaI sites in pIK1.1, and were subsequently excised and insertedbetween analogous EcoRI and ApaI sites of pRT43.2F3, described in U.S.patent application Ser. No. 08/258,152 incorporated herein in itsentirety by reference, generally as two subfragments to avoid internalEcoRI or ApaI sites within the CPR constructs. One skilled in the artcan readily devise schemes for producing retroviral vectors containingother CPRs.

b) Infection of Human CD8⁺ T Cells With CPR-Expressing RetroviralVectors

Human CD8⁺ T lymphocytes were isolated from peripheral blood lymphocytes(PBL) obtained from healthy donors by purification with the CEPRATE LCsystem (CellPro, Inc., Bothell, Wash.), followed by negative selectionagainst CD4⁺ cells using a T-25 MicroCELLector (AIS, Inc., Santa Clara,Calif.). The final purified cell population contained greater than 98%CD8⁺ cells according to FACS analysis. Immediately after purification,cells were stimulated for 24 hours with an equal number of γ-irradiatedautologous PBMCs in AIM-V media (GibcoBRL, Grand Island, N.Y.)containing 10 ng/μl of OKT3 MAb and 100 units of human IL-2 (ChironCorp., Emeryville, Calif.). Cells were then washed free of OKT3 andcultured in AR media (50% AIM-V, 50% RPMI, 4 mM Glutamine, 20 mM Hepes,1 mM Na-Pyruvate, non-essential amino acids, and 100 units human IL-2)supplemented with 5% heat inactivated human AB plasma (Sigma, St. Louis,Mo.). Retrovirus was prepared in the TIN-4 cell line derived fromthymidine kinase-expressing human 293 cells. For the transduction ofhuman CD8⁺ cells, TIN-4 cells were seeded at 5×10⁵ cell/plate in 6-wellplates (Corning Glass, Corning, N.Y.) in complete DMEM medium 48 hoursprior to transfection. Ten micrograms of CPR construct in the retroviralvector pRT43.2 were transfected per plate in the absence or presence ofpackaging plasmids by the calcium phosphate coprecipitation method.Following transfection, 1.5 ml of fresh AR medium containing 100units/ml of human IL-2 was added to each well of the plate. Three hourslater, 5×10⁵ of CD8⁺ T cells in AR media containing 100 units/ml ofhuman IL-2 and 2 μg/ml of polybrene were added to each well of theplate. CD8⁺ T cells were removed from the 6-well plates 24 hours laterand then transduced a second time by the same procedure. Newlytransduced CD8⁺ T cells were maintained in AR media.

c) FACS Analysis of CPR Expression in Human CD8⁺ T Cells

At various times following transduction, CD8⁺ T cells were harvested andwashed with PBS/1% FCS. Approximately 1×10⁶ CD8⁺ T cells were stainedwith specific antibodies for FACS analysis as described in Example 10B.As shown in Table 1, chimeric proliferation receptors can be expressedon the surface of CD8⁺ T cells.

                  TABLE I                                                         ______________________________________                                        Transduction % Positive in CD8.sup.+  T Cells                                 ______________________________________                                        Mock         1.7                                                              CD4-ζ   18.2                                                             CD4-mJAK1    4.0                                                              CD4-mJAK3    3.8                                                              CD4-hTyk2    7.5                                                              CD4-ζ-hTyk2                                                                           4.6                                                              ______________________________________                                    

d) Immunoprecipitation Analysis of CPR Expression in Human CD8⁺ T Cells

At various times following transduction, human CD8⁺ T cells areharvested and placed in methionine-depleted AR media supplemented with200 μCi ³⁵ S!-methionine (1160 Ci/mmol, ICN Biomedicals, Inc.). Cellsare lysed in RIPA buffer, precleared with 10 μl Pansorbin (except cellsexpresssed SAb-containing CPRs) (Calbiochem, La Jolla, Calif.), and thenincubated with either OKT4A (Ortho Diagnostic Systems), polyclonalanti-mouse/human JAK1 (UBI, Lake Placid, N.Y.), polyclonal anti-mouseJAK2 (UBI), or polyclonal anti-mouse JAK3 (UBI) at 4° C. for 1 hour. Tenmicroliters of Pansorbin are then added to the lysates to precipitatethe antibody-bound antigen. The immunoprecipitates are washed threetimes in RIPA buffer, boiled in SDS sample buffer and analyzed by 7.5%SDS-polyacrylamide gel etectrophoresis. Gels are fixed in 20%methanol/10% acetic acid and then soaked in Enlightening solution (NENResearch Products, Boston, Mass.) for 15 minutes, dried and subjected toautoradiography. SDS-PAGE analysis reveals the molecular mass of CPRsexpressed in human CD8⁺ T cells.

e) Analysis of CPR-Expressing Human CD8⁺ T Cells for PhosphotyrosineContent

To assess the phosphotyrosine content of human CD8⁺ T cells expressingCPRs, 5×10⁶ cells are lysed in protein phosphotyrosine lysis buffer (1%Nonidet P-40, 150 mM NaCl, 10 mM Tris-HCl, pH 7.5, 1 mMphenylmethylsulfonyl fluoride, 10 μg/ml aprotinin, 10 μg/ml pepstatin,100 uM orthovanadate) at 4° C. for 15 min, and immunoprecipitated witheither OKT4A, anti-human/mouse JAK1, anti-mouse JAK2, anti-mouse JAK3,anti-human JAK3 or anti-human-Tyk2. The immunoprecipitates are separatedby 7.5% SDS-PAGE and the proteins are transferred electrophoretically toa nitrocellulose membrane in transfer buffer (20 mM Tris, 150 mMglycine, 20% methanol, 0.2% SDS) at 50 volts for 4 hours. Membranes areblocked in TBST (10 mM Tris-HCl, pH 8, 150 mM NaCl, 0.05% Tween-20)containing 1% BSA and then incubated with primary anti-phosphotyrosineantibody 4G10 (UBI). The membrane is developed using the enhancedchemiluminescence (ECL) detection system (Amersham, Arlington Height,Ill.).

f) Analysis of CPR-Expressing Human CD8⁺ T Cell Lysates for in VitroKinase Activity

As JAK kinases have the ability to be autophosphorylated, human CD8⁺ Tcells expressing CPRs are evaluated for their CPR-associated tyrosinekinase activity. Immunoprecipitates prepared from CPR-transduced humanCD8⁺ T cells using either OKT4A, anti-human Fc Mab, anti-human/mouseJAK1, anti-mouse JAK2, anti-mouse JAK3, anti-human JAK3 oranti-human-Tyk2, as described above, are washed three times with proteintyrosine lysis buffer and once with kinase buffer (10 mM MnCl₂, 50 mMTris-HCl, pH 7.5). Kinase reactions are performed in 25 μl of kinasebuffer containing 10 μCi γ- 32-P!ATP (95,000 Ci/mmole, Amersham).Following a 5 minute incubation at 25° C., the reactions are terminatedby addition of equal volume of 2×SDS sample buffer, boiled for 5 minutesand subjected to SDS-PAGE. The gel is fixed, treated with 1M KOH at 55°C. for 1 hour to remove serine/threonine phosphorylated residues,refixed, dried and subjected to autoradiography.

g) Proliferative Response of CPR-Expressing Human CD8⁺ T Cells

To evaluate the ability of CPR-expressing CD8⁺ T cells to proliferate inan antigen-driven or inducer molecule-driven fashion, cells are firstrested by serum starvation for 16 hours. Cells are then placed inculture dishes coated with saturating concentrations of either OKT4A,anti-human Fc Mab, gp120, gp160-expressing cells, gp41/gp120-expressingcells, HIV-1 infected cells or FK1012. After 5 to 48 hours, the totalcell numbers is determined by counting, following staining with trypanblue/PBS. The cell number is compared with the original cell number, andthe cell numbers obtained after starvation with or without stimulationwith media containing human serum. In addition, analysis of cellularproliferation is carried out by measuring radioactive thymidineincorporation. Cells are starved for 16 hours and aliquoted inquadruplicate into microliter plates at 5×10⁴ cells/well. The plates areeither coated with OKT4A or anti-gp120, gp160-expressing cells,gp41/gp120-expressing cells, HIV-1 infected cells or FK1012. Cells arecultured under these conditions for up to three days, and thymidineincorporation is measured in a liquid scintillation counter afterpulsing the cells for the last 8 hours with 1 μCi/well of ³⁵ H!thymidine (NEN Corp, Boston, Mass.).

h) C-myc Induction in CPR-Expressing Human CD8⁺ T Cells

To evaluate the induction of the c-myc proto-oncogene in CPR-expressingCD8⁺ T cells stimulated with a specific antigen or inducer molecule,mRNA is prepared using a Fast Track mRNA isolation kit (Invitrogen, SanDiego, Calif.). Two micrograms of mRNA is denatured withformaldehyde/formamide and run on a 1% agarose-formaldehyde gel asdescribed (Sambrook et al, Molecular Cloning, Cold Spring HarborLaboratory Press, 1989). The mRNA is transferred overnight by capillaryaction to a nitrocellulose membrane (Schleicher and Schuell, Keene,N.H.) in 10×SSC buffer. The membrane is hybridized overnight with ac-myc probe at 65° C. in 6×SSC, 0.5% sodium dodecyl sul fate and 100mg/ml of denatured herring sperm DNA, washed in 0.2×SSC and subjected toautoradiography. The c-myc probe is prepared with a 1 kb ClaI-EcoRIfragment obtained from pMyc6514 (Battey et al, Cel 134, 779-787, 1983)which contains the third exon of human c-myc. Radiolabelling of theprobe is carried by random priming with E. coli. DNA polymerase, dNTPsand α 32-P! dCTP (3000 Ci/mmole, Amersham, Arlington Heights, Ill.) asdescribed (Sambrook et al). As a control for the amount of RNA loaded onthe gel, the nitrocellulose membrane is rehybridized with a 1.3 kb mouseβ-actin probe (Stratagene, La Jolla, Calif.). A PhosphoImager (MolecularDevices, Menlo Park, Calif.) is used to quantitate the amount of probebound to the membrane.

i) Calcium Mobilization Response in CPR-Expressing Human CD8⁺ T Cells

The mobilization of intracellular Ca²⁺ ! by CPR-expressing human CD8⁺ Tcells is measured using Indo-1 acetomethoxyester (Molecular Probes,Eugene, Oreg.) on a FACStar Plus (Beckton Dickinson). Cells arecollected by centrifugation, resuspended at 3×10⁶ /ml in complete mediumcontaining 1 mM Indo-1 (Grynkiewicz et al., (1985) J. Biol. Chem.260:3440-3450) and incubated at 37° C. for 45 min. The Indo-1-loadedcells are pelleted and resuspended at 1×10⁶ /ml in serum-free medium.Cells are then stimulated by treatment with either saturating levels ofOKT4A or anti-human Fc Mab and cross-linking goat anti-mouse IgG, gp120, gp160-expressing cells, HIV-1 infected cells or FK1012, andfluorescence is measured. Maximal fluorescence is determined after lysisof cells with Triton X-100; minimal fluorescence is obtained afterchelation of Ca²⁺ with EGTA. Intracellular Ca²⁺ ! is determined usingthe following equation: Ca²⁺ !=K_(d) (F_(observed-) F_(min))/(F_(max)-F_(observed)), with K_(d) =250 nM as described (Grynkiewicz, 1985).

j) Cytolytic Activity of CPR-Expressing Human CD8⁺ T Cells

To determine the cytolytic activity of CPR-expressing human CD8⁺ Tcells, in vitro cytolytic assays are carried out with target cellsexpressing HIV-1 antigens. Gp160-expressing 293 cells or HIV-1 infectedhuman T cells are labeled at 37° C. overnight with 10μCi ³ H! TdR(Roberts et al., Blood 84:2878-2889 (1994)), washed and aliquoted to96-well V-bottom plates at 1×10⁴ /well. Serial dilutions ofCPR-expressing human CD8⁺ T cells are made to achieve an effector totarget (E:T) ratio ranging from 100:1 to 0.1:1. Sample are set up intriplicate and incubations are carried out for 6 hours at 37° C.Following incubation, aliquots of the culture supernatant are removedand counted in a liquid scintillation counter. Spontaneous release (SR)is obtained in a negative control sample lacking CPR-expressing humanCD8⁺ T cells; maximum release (MR) is obtained from a positive controlsample by lysing target cells with 1N HCl. The percent specific lysis iscalculated from the following equation: % specific lysis=SR_(cpm)-Sample_(cpm))/(Sample_(cpm) -MR_(cpm))×100%.

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication or patent application was specificallyand individually indicated to be incorporated by reference.

The invention now being fully described, it will be apparent to one ofordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit or scope of the appendedclaims.

    __________________________________________________________________________    SEQUENCE LISTING                                                              (1) GENERAL INFORMATION:                                                      (iii) NUMBER OF SEQUENCES: 31                                                 (2) INFORMATION FOR SEQ ID NO:1:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 39 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:                                       CCTGCTGAACTTCACTCTGTCGACACAGAAGAAGATGCC39                                     (2) INFORMATION FOR SEQ ID NO:2:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 40 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:                                       TCGACATGCAGTATCTAAATATAAAAGAGGACTGCAATGC40                                    (2) INFORMATION FOR SEQ ID NO:3:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 40 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:                                       CATGGCATTGCAGTCCTCTTTTATATTTAGATACTGCATG40                                    (2) INFORMATION FOR SEQ ID NO:4:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 21 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:                                       TATGTGTCAGTGGGGCGGGCC21                                                       (2) INFORMATION FOR SEQ ID NO:5:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 15 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:                                       CGCCCCACTGACACA15                                                             (2) INFORMATION FOR SEQ ID NO:6:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 41 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:                                       GTAAGGCAGGCCATTCCCATGTCGACACAGAAGAAGATGCC41                                   (2) INFORMATION FOR SEQ ID NO:7:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:                                       TCTGTGTCGACATGGG16                                                            (2) INFORMATION FOR SEQ ID NO:8:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 45 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:                                       TCGACATGGCACCTCCAAGTGAGGAGACACCTCTGATCCCTCAGC45                               (2) INFORMATION FOR SEQ ID NO:9:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 41 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:                                       GCTGAGGGATCAGAGGTGTCTCCTCACTTGGAGGTGCCATG41                                   (2) INFORMATION FOR SEQ ID NO:10:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 23 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:                                      GATCCCTAGTTTATTCATGGGCC23                                                     (2) INFORMATION FOR SEQ ID NO:11:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 15 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:                                      CATGAATAAACTAGG15                                                             (2) INFORMATION FOR SEQ ID NO:12:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 42 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:                                      CATCCCCCAGTGGCGCAGAGGCATGTCGACAGAGTGAAGTTC42                                  (2) INFORMATION FOR SEQ ID NO:13:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:                                      GTCGACATGCCTCTGC16                                                            (2) INFORMATION FOR SEQ ID NO:14:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 39 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:                                      GGGCCGCCGGAATTCCATGTCGACACAGAAGAAGATGCC39                                     (2) INFORMATION FOR SEQ ID NO:15:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:                                      TCTGTGTCGACATGGA16                                                            (2) INFORMATION FOR SEQ ID NO:16:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 17 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:16:                                      CCTCAACAGGGTCCTTC17                                                           (2) INFORMATION FOR SEQ ID NO:17:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 30 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17:                                      GCTGATCGTCGACAACTGCAGGAACACCGG30                                              (2) INFORMATION FOR SEQ ID NO:18:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 31 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:18:                                      CATCTGTGATATCTCTACACCAAGTGAGTTG31                                             (2) INFORMATION FOR SEQ ID NO:19:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 40 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:19:                                      GAAGAGCAAGCGCCATGTTGAAGCCATCATTACCATTCAC40                                    (2) INFORMATION FOR SEQ ID NO:20:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 40 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:20:                                      AGCCTGAAACCTGAACCCCAATCCTCTGACAGAAGAACCC40                                    (2) INFORMATION FOR SEQ ID NO:21:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 49 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:21:                                      CTGGCTGGTCGACGAACGGACGATGCCCCGCATTCCCACCCTGAAGAAC49                           (2) INFORMATION FOR SEQ ID NO:22:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 32 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:22:                                      GATTGGGGGATATCTCAGGTTTCAGGCTTTAG32                                            (2) INFORMATION FOR SEQ ID NO:23:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 42 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:23:                                      GAAATCCCCTGGCTGTTAGTCGACGCGAGGGGGCAGGGCCTG42                                  (2) INFORMATION FOR SEQ ID NO:24:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 16 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:24:                                      TGTTAGTCGACGCGAG16                                                            (2) INFORMATION FOR SEQ ID NO:25:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 30 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:25:                                      GGTCCACTCGAGATGGCCAGCAGCGGCATG30                                              (2) INFORMATION FOR SEQ ID NO:26:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 41 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:26:                                      CCAGGTCCGATATCTTAGTCGACGTTCACCACGTCATAGTA41                                   (2) INFORMATION FOR SEQ ID NO:27:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 32 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:27:                                      GACTGACTCTCGAGGGCGTGCAGGTGGAAACC32                                            (2) INFORMATION FOR SEQ ID NO:28:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 32 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:28:                                      GACTGACTGTCGACTTCCAGTTTTAGAAGCTC32                                            (2) INFORMATION FOR SEQ ID NO:29:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 18 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:29:                                      AATTCAAGGCCACAATGC18                                                          (2) INFORMATION FOR SEQ ID NO:30:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 18 base pairs                                                     (B) TYPE: nucleic acid                                                        (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: DNA (genomic)                                             (xi) SEQUENCE DESCRIPTION: SEQ ID NO:30:                                      TCGAGCATTGTGGCCTTG18                                                          (2) INFORMATION FOR SEQ ID NO:31:                                             (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 14 amino acids                                                    (B) TYPE: amino acid                                                          (C) STRANDEDNESS: single                                                      (D) TOPOLOGY: linear                                                          (ii) MOLECULE TYPE: peptide                                                   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:31:                                      GlySerThrSerGlySerGlyLysSerSerGluGlyLysGly                                    1510                                                                          __________________________________________________________________________

What is claimed is:
 1. A chimeric DNA sequence encoding a membrane boundprotein, said DNA sequence comprising in reading frame:a DNA sequenceencoding a signal sequence; a DNA sequence encoding an extracellularinducer-responsive clustering domain that binds specifically to at leastone inducer molecule which results in the dimerization oroligomerization of said extracellular domain; a DNA sequence encoding atransmembrane domain; and a DNA sequence encoding a proliferationsignaling domain comprising a Janus tyrosine kinase, wherein when saidchimeric DNA sequence is expressed as a membrane bound protein in aselected host cell under conditions suitable for expression, saidmembrane bound protein initiates a signal for proliferation in said hostcell on binding to an inducer molecule.
 2. The DNA sequence according toclaim 1 wherein said extracellular inducer responsive clustering domainis an antibody or single-chain antibody or portions or modificationsthereof containing inducer binding and clustering activity.
 3. The DNAsequence according to claim 1 wherein said extracellular inducerresponsive clustering domain is a cell differentiation antigen.
 4. TheDNA sequence according to claim 3 wherein said cell differentiationantigen is selected from the group consisting of CD4 or CD8.
 5. The DNAsequence according to claim 1 wherein said transmembrane domain isnaturally associated with said extracellular inducer responsiveclustering domain.
 6. An expression cassette comprising atranscriptional initiation region, a DNA sequence according to claim 1under the transcriptional control of said transcriptional initiationregion and a transcriptional termination region.
 7. The expressioncassette according to claim 6 wherein said transcriptional initiationregion is functional in a mammalian host.
 8. A cell comprising a DNAsequence according to claim
 1. 9. A cell comprising a DNA sequence thatencodes a chimeric effector function receptor comprising anextracellular inducer-responsive clustering domain, a transmembranedomain, and a effector function signaling domain and further comprisinga second DNA sequence according to claim
 1. 10. The cell according toclaim 8 or 9 wherein said cell is a mammalian cell.
 11. The cellaccording to claim 8 or 9 wherein said cell is a human cell.
 12. Achimeric protein comprising in the N-terminal to C-terminal direction:anextracellular inducer-responsive clustering domain consisting of aportion of a surface membrane protein or secreted protein that bindsspecifically to at least one inducer-molecule which results in thedimerization or oligomerization of said extracellular domain:atransmembrane domain; and a proliferation signaling domain comprising aJanus tyrosine kinase, wherein when said chimeric protein is expressedas a membrane bound protein in a selected host cell under conditionssuitable for expression, said membrane bound protein initiates a signalfor proliferation in said host cell on binding to an inducer molecule.